ASTM D4956-19

Standard Specification for Retroreflective Sheeting for Traffic Control

SCOPE
1.1 This specification covers flexible, non-exposed glass-bead lens and microprismatic, retroreflective sheeting designed for use on traffic control signs, delineators, barricades, and other devices. This specification does not address inks, overlays, or other imaging methods that may be applied to retroreflective sheeting material to create traffic signs or other devices.  
1.2 Although this specification provides photometric requirements for retroreflective sheeting under evaluation, minimum performance requirements of in-service signs or other devices are outside the scope of this document.  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.4 The following safety hazards caveat pertains only to the test methods portion, Section 7, of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2019
• ICS: 93.080.30 - Road equipment and installations
• Technical Committee: D04 - Road and Paving Materials
• Drafting Committee: D04.38 - Highway Traffic Control Materials

Relations

• Replaces: ASTM D4956-17 - Standard Specification for Retroreflective Sheeting for Traffic Control
• Effective Date: 01-Jul-2019
• Refers: ASTM D2794-93(2024) - Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact)
• Effective Date: 15-Jan-2024
• Refers: ASTM E808-23 - Standard Practice for Describing Retroreflection
• Effective Date: 01-Dec-2023
• Refers: ASTM E1247-12(2023) - Standard Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
• Effective Date: 01-Nov-2023
• Refers: ASTM E1164-23 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 01-Nov-2023
• Refers: ASTM E811-09(2020)e1 - Standard Practice for Measuring Colorimetric Characteristics of Retroreflectors Under Nighttime Conditions
• Effective Date: 15-Jun-2020
• Refers: ASTM E1347-06(2020) - Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
• Effective Date: 01-May-2020
• Refers: ASTM E3165-18 - Standard Test Method for Nighttime Retroreflected Chromaticity of Retroreflective Sheeting
• Effective Date: 01-Jul-2018
• Refers: ASTM E1247-12(2017) - Standard Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
• Effective Date: 01-Nov-2017
• Refers: ASTM G147-17 - Standard Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
• Effective Date: 01-Jun-2017
• Refers: ASTM E308-17 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-May-2017
• Refers: ASTM E808-01(2016) - Standard Practice for Describing Retroreflection
• Effective Date: 01-Jan-2016
• Refers: ASTM E1347-06(2015) - Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
• Effective Date: 01-Nov-2015
• Refers: ASTM E811-09(2015) - Standard Practice for Measuring Colorimetric Characteristics of Retroreflectors Under Nighttime Conditions
• Effective Date: 01-Jul-2015
• Refers: ASTM E308-15 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-Apr-2015

Overview

ASTM D4956-19 is a comprehensive standard published by ASTM International, establishing requirements for retroreflective sheeting used in traffic control applications. This specification sets the performance criteria for flexible, non-exposed glass-bead lens and microprismatic retroreflective sheetings intended for use on traffic control signs, delineators, barricades, and similar devices. The standard is widely recognized and referenced by transportation agencies to ensure traffic signs remain highly visible and durable under various environmental conditions.

Key Topics

• Material Types: Covers both glass-bead lens and microprismatic retroreflective sheeting.
• Performance Requirements: Details minimum levels for retroreflectivity, color, luminance, durability, colorfastness, shrinkage, adhesion, flexibility, liner removal, and impact resistance.
• Classification System: Defines multiple types (I, II, III, IV, V, VI, VIII, IX, XI) with distinct performance characteristics and typical applications:
  • Type I-III, IV, VIII, IX, XI: Primarily for permanent highway signing, construction zones, and delineators.
  • Type V: Intended for delineators.
  • Type VI: Targeted for temporary roll-up warning signs, traffic cone collars, and post bands.
• Adhesive Classes: Specifies five backing/adhesive classes, including pressure-sensitive, heat-activated, low-tack, and non-adhesive types for varied installation needs.
• Test Methods and Conditions: References standardized ASTM procedures for evaluating retroreflective sheeting, including:
  • Coefficient of retroreflection (ASTM E810)
  • Color and luminance measurement (ASTM E308, E1347, E1349)
  • Weathering (ASTM G7, G151, G155)
  • Impact resistance (ASTM D2794)

Applications

• Traffic Signs: Ensures long-term visibility and legibility for regulatory, warning, and guidance signs on highways, streets, and rural roads.
• Work Zone Devices: Provides specifications for retroreflective sheeting used on barricades, channelizers, and other temporary traffic control devices.
• Delimiters and Markers: Supports the effective use of reflective markers and delineators to guide drivers, especially in nighttime or low-light conditions.
• Temporary Traffic Devices: Type VI sheeting is specifically designed for devices that are frequently moved or adjusted, such as roll-up signs and traffic cone collars.
• Public Safety: Enhances overall road safety by maintaining the visibility of traffic control devices regardless of weather, lighting, and environmental factors.

Related Standards

• ASTM B209 / B209M: Specifications for aluminum and aluminum-alloy sheet and plate - common substrates for traffic signs.
• ASTM B449: Specification for chromates on aluminum.
• ASTM D2794: Test method for impact resistance of organic coatings.
• ASTM E808, E810, E3165: Methods for measuring retroreflection.
• ASTM E308, E1347, E1349, E2301: Protocols for color and luminance measurement.
• ASTM G7, G151, G155: Procedures for accelerated weathering and environmental exposure.
• ISO 4892-2: Plastics - exposure to laboratory light sources (xenon-arc lamps).
• EN 12899-1: European standard for fixed, vertical road traffic signs.

Practical Value

By adhering to ASTM D4956-19, manufacturers and agencies can ensure the retroreflective sheeting used on traffic control devices meets rigorous standards for visibility, durability, and performance. End users benefit from increased road safety and lower maintenance costs due to the enhanced longevity and reliability of traffic signs and markers. The standard also facilitates international trade and regulatory compliance by aligning with globally recognized measurement methods and performance benchmarks for retroreflective materials.

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Keywords: ASTM D4956, retroreflective sheeting, traffic control, traffic signs, highway signing, microprismatic, glass-bead lens, road safety, sign durability, roadside delineators, performance specification.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D4956 −19
Standard Specification for
Retroreflective Sheeting for Traffic Control
This standard is issued under the fixed designation D4956; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope B209Specification for Aluminum and Aluminum-Alloy
Sheet and Plate
1.1 This specification covers flexible, non-exposed glass-
B209MSpecification for Aluminum and Aluminum-Alloy
beadlensandmicroprismatic,retroreflectivesheetingdesigned
Sheet and Plate (Metric)
for use on traffic control signs, delineators, barricades, and
B449Specification for Chromates on Aluminum
other devices. This specification does not address inks,
D2794Test Method for Resistance of Organic Coatings to
overlays, or other imaging methods that may be applied to
the Effects of Rapid Deformation (Impact)
retroreflective sheeting material to create traffic signs or other
E284Terminology of Appearance
devices.
E308PracticeforComputingtheColorsofObjectsbyUsing
1.2 Although this specification provides photometric re-
the CIE System
quirements for retroreflective sheeting under evaluation, mini-
E808Practice for Describing Retroreflection
mum performance requirements of in-service signs or other
E810Test Method for Coefficient of Retroreflection of
devices are outside the scope of this document.
Retroreflective Sheeting Utilizing the Coplanar Geometry
1.3 The values stated in inch-pound units are to be regarded
E811Practice for Measuring Colorimetric Characteristics of
as standard. The values given in parentheses are mathematical
Retroreflectors Under Nighttime Conditions
conversions to SI units that are provided for information only
E991Practice for Color Measurement of Fluorescent Speci-
and are not considered standard.
mens Using the One-Monochromator Method
1.4 The following safety hazards caveat pertains only to the
E1164PracticeforObtainingSpectrometricDataforObject-
test methods portion, Section 7, of this specification. This
Color Evaluation
standard does not purport to address all of the safety concerns,
E1247Practice for Detecting Fluorescence in Object-Color
if any, associated with its use. It is the responsibility of the user
Specimens by Spectrophotometry
of this standard to establish appropriate safety, health, and
E1347Test Method for Color and Color-Difference Mea-
environmental practices and determine the applicability of
surement by Tristimulus Colorimetry
regulatory limitations prior to use.
E1349Test Method for Reflectance Factor and Color by
1.5 This international standard was developed in accor-
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
dance with internationally recognized principles on standard-
Geometry
ization established in the Decision on Principles for the
E2152Practice for Computing the Colors of Fluorescent
Development of International Standards, Guides and Recom-
Objects from Bispectral Photometric Data
mendations issued by the World Trade Organization Technical
E2153Practice for Obtaining Bispectral Photometric Data
Barriers to Trade (TBT) Committee.
for Evaluation of Fluorescent Color
E2301Test Method for Daytime Colorimetric Properties of
2. Referenced Documents
Fluorescent Retroreflective Sheeting and Marking Mate-
2.1 ASTM Standards:
rials for High Visibility Traffic Control and Personal
Safety Applications Using 45°:Normal Geometry
E3165TestMethodforNighttimeRetroreflectedChromatic-
This specification is under the jurisdiction ofASTM Committee D04 on Road
and Paving Materials and is the direct responsibility of Subcommittee D04.38 on
ity of Retroreflective Sheeting
Highway Traffic Control Materials.
G7/G7MPractice forAtmospheric Environmental Exposure
CurrenteditionapprovedJuly1,2019.PublishedJuly2019.Originallyapproved
Testing of Nonmetallic Materials
in 1989. Last previous edition approved in 2017 as D4956–17. DOI: 10.1520/
D4956-19.
G113Terminology Relating to Natural andArtificialWeath-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ering Tests of Nonmetallic Materials
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
G147Practice for Conditioning and Handling of Nonmetal-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. lic Materials for Natural and Artificial Weathering Tests
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4956−19
G151PracticeforExposingNonmetallicMaterialsinAccel- mentmaterial.Applicationsforthismaterialincludepermanent
erated Test Devices that Use Laboratory Light Sources highway signing, construction zone devices, and delineators.
G155Practice for Operating XenonArc LightApparatus for
4.2.2 Type II—A retroreflective sheeting referred to as
Exposure of Non-Metallic Materials
“super engineer grade” that is typically an enclosed lens
glass-bead retroreflective material or a microprismatic retrore-
2.2 Other Standards:
flectiveelementmaterial.Applicationsforthismaterialinclude
ISO 4892-2:2006Plastics—Methods of Exposure to Labo-
permanent highway signing, construction zone devices, and
ratory Light Sources—Part 2: Xenon-Arc Lamps
delineators.
ISO 4892-2:2006/Amd.1:2009Plastics—Methods of Expo-
sure to Laboratory Light Sources—Part 2: Xenon-Arc 4.2.3 Type III—A retroreflective sheeting referred to as
Lamps “high-intensity” that is typically manufactured as an encapsu-
EN 12899-1:2007Fixed, Vertical Road Traffic Signs—Part lated glass-bead retroreflective material or as a microprismatic
1: Fixed Signs retroreflective element material. Applications for this material
includepermanenthighwaysigning,constructionzonedevices,
3. Terminology and delineators.
4.2.4 Type IV—A retroreflective sheeting referred to as
3.1 Definitions—Definitions of terms are as described in
“high-intensity” that is typically an unmetalized micropris-
Terminology E284, Practice E808, and Terminology G113.
matic retroreflective element material. Applications for this
3.2 Definitions of Terms Specific to This Standard:
material include permanent highway signing, construction
3.2.1 reboundable sheeting, n—retroreflective material in-
zone devices, and delineators.
tended to be attached to flexible, impact-resistant plastic
4.2.5 Type V—A retroreflective sheeting referred to as “su-
devices, such as traffic drum-like channelizing devices.
per high-intensity” that is typically a metalized microprismatic
4. Classification retroreflectiveelementmaterial.Thissheetingistypicallyused
for delineators.
4.1 Retroreflective sheeting shall consist of a white or
4.2.6 Type VI—Anelastomericretroreflectivesheetingwith-
colored sheeting having a smooth outer surface and that
out adhesive. This sheeting is typically a vinyl microprismatic
essentially has the property of a retroreflector over its entire
retroreflectivematerial.Applicationsincludeorangetemporary
surface. There are nine types and five classes of retroreflective
roll-up warning signs, traffic cone collars, and post bands.
sheeting. Types are determined by conformance to the
4.2.7 Type VII—The use of a designation as Type VII has
retroreflectance,color,anddurabilityrequirementslistedin6.1
been discontinued.
and may be of any construction providing that those require-
4.2.8 Type VIII—A retroreflective sheeting typically manu-
ments are met. Type designation is provided as a means for
differentiating functional performance. Typical examples of facturedasanunmetalizedcubecornermicroprismaticretrore-
flectiveelementmaterial.Applicationsforthismaterialinclude
applications are provided for descriptive information only and
are not intended to be limitations or recommendations. Com- permanent highway signing, construction zone devices, and
delineators.
mon identifiers for each type are listed in 4.2.
4.1.1 The typical applications for the retroreflective sheet-
4.2.9 Type IX—Aretroreflectivesheetingtypicallymanufac-
ing addressed in this specification are: tured as an unmetalized cube corner microprismatic retrore-
flectiveelementmaterial.Applicationsforthismaterialinclude
Type Typical Application
permanent highway signing, construction zone devices, and
I Highway signing, construction-zone devices, and delineators
delineators.
II Highway signing, construction-zone devices, and delineators
4.2.10 Type X—TheuseofadesignationasTypeXhasbeen
III Highway signing, construction-zone devices, and delineators
IV Highway signing, construction-zone devices, and delineators
discontinued.
V Delineators
4.2.11 Type XI—A retroreflective sheeting typically manu-
VI Temporary roll-up signs, warning signs, traffic cone collars, and post
bands
facturedasanunmetalizedcubecornermicroprismaticretrore-
VII This type designation has been replaced with Type VIII
flectiveelementmaterial.Applicationsforthismaterialinclude
VIII Highway signing, construction-zone devices, and delineators
permanent highway signing, construction zone devices, and
IX Highway signing, construction-zone devices, and delineators
X This type designation has been replaced with Type VIII
delineators.
XI Highway signing, construction-zone devices, and delineators
NOTE 1—All retroreflective sheetings, but especially microprismatic
4.2 Retroreflective sheeting shall be classified as follows
sheetings, may have unique performance characteristics outside of the
(the type sequence is not indicative of performance level):
range of the standard geometries presented in the tables that define the
4.2.1 Type I—A retroreflective sheeting referred to as “en-
types. Certain applications may require the use of a particular product
gineering grade” that is typically an enclosed lens glass-bead within a particular type in order to achieve a desired level of retroreflec-
tivity in a given situation. In these cases, information concerning
retroreflective material or a microprismatic retroreflective ele-
additional performance characteristics must be obtained.
4.3 Backing Classes—The backing required for retroreflec-
Available from International Organization for Standardization (ISO), ISO
tive sheeting shall be classified as follows:
Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
4.3.1 Class 1—The adhesive backing shall be pressure
Geneva, Switzerland, http://www.iso.org.
sensitive, require no heat, solvent, or other preparation for
Available from European Committee for Standardization (CEN), Avenue
Marnix 17, B-1000, Brussels, Belgium, http://www.cen.eu. adhesion to smooth, clean surfaces.
D4956−19
4.3.2 Class 2—Theadhesivebackingshallhaveanadhesive 6.1.1 Type I—Minimum Coefficient of Retroreflection—
that shall be activated by applying heat and pressure to the Table 1; Outdoor Weathering—24 months, see 6.4; Daytime
material. The temperature necessary to form a durable perma- Luminance Factor—Table 2; Other requirements:When sheet-
nent bond shall be a minimum of 150°F (66°C). ing is specified for construction work zone applications, the
outdoor weathering shall be twelve months.
4.3.2.1 The Class 2 material shall be repositionable under
normal shop conditions and at substrate temperatures up to 6.1.2 Type II—Minimum Coefficient of Retroreflection—
Table 3; Outdoor Weathering—36 months, see 6.4; Daytime
100°F (38°C) and without damage to the material. The Class
2 material may be perforated to facilitate removal of air in Luminance Factor—Table 2; Other requirements:When sheet-
ing is specified for construction work zone applications, the
heat-vacuum laminators, but the perforations must be of a size
and frequency such that they do not cause objectionable outdoor weathering shall be twelve months.
6.1.3 Type III—Minimum Coefficient of Retroreflection—
blemishes when the sheeting is printed.
Table 4; Outdoor Weathering—36 months, see 6.4; Daytime
4.3.3 Class 3—The adhesive backing shall have a
Luminance Factor—Table 2; Other requirements:When sheet-
positionable, low-tack, pressure-sensitive adhesive that re-
ing is specified for construction work zone applications, the
quires no heat, solvent, or other preparation for adhesion to
outdoor weathering shall be twelve months.
smooth, clean surfaces. It shall be repositionable up to a
6.1.4 Type IV—Minimum Coefficient of Retroreflection—
temperature of 100°F (38°C) without damage to the material.
Table 5; Outdoor Weathering—36 months, see 6.4; Daytime
4.3.4 Class 4—The adhesive backing shall have a low-
Luminance Factor—Table 2; Other requirements:When sheet-
temperature, pressure-sensitive adhesive that permits sheeting
ing is specified for construction work zone applications, the
applications at temperatures down to +20°F (−7°C) without
outdoor weathering shall be twelve months.
the aid of heat, solvent, or other preparation for adhesion to
6.1.5 Type V—Minimum Coefficient of Retroreflection—
smooth, dry, clean surfaces.
Table 6; Outdoor Weathering—36 months, see 6.4; Daytime
4.3.5 Class 5—Thisshallbeanonadhesivebackingmadeof
Luminance Factor—Table 2; Other requirements:When sheet-
material commercially used for self-supporting products such
ing is specified for construction work zone applications, the
as traffic cone collars, temporary roll-up warning signs, and
outdoor weathering shall be twelve months.
post bands.
6.1.6 Type VI—Minimum Coefficient of Retroreflection—
Table 7; Outdoor Weathering—six months, see 6.4; Daytime
5. Ordering Information
Luminance Factor—Table 2.
5.1 The purchaser using this specification shall include the
6.1.7 Type VII—Retroreflective sheeting materials previ-
following information:
ously classified as Type VII have been reclassified as Type
5.1.1 ASTM designation (D4956),
VIII.
5.1.2 Classification type (see Section 4),
6.1.8 Type VIII—Minimum Coefficient of Retroreflection—
5.1.3 Adhesive class (see 4.3),
Table 8; Outdoor Weathering—36 months, see 6.4; Daytime
5.1.4 Daytime color (see 6.3),
Luminance Factor—Table 2; Other requirements:When sheet-
5.1.5 Length and width of sheets (see 8.1),
ing is specified for construction work zone applications, the
5.1.6 Length and width of rolls (see 8.2),
outdoor weathering shall be twelve months.
5.1.7 Supplementary information, if required by the 6.1.9 Type IX—Minimum Coefficient of Retroreflection—
purchaser, including: Table 9; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements:When sheet-
5.1.7.1 Compliance with the minimum coefficient of ret-
roreflection for 0.1° observation angle is a supplementary ing is specified for construction work zone applications, the
outdoor weathering shall be twelve months.
requirement which shall apply only when specified.An obser-
vation angle of 0.1° may be specified where the long-distance 6.1.10 Type X—Retroreflective sheeting materials previ-
ously classified asType X have been reclassified asTypeVIII.
performance of a sheeting is to be a requirement,
6.1.11 Type XI—Minimum Coefficient of Retroreflection—
5.1.7.2 Fungus-resistance testing requirements (see Supple-
Table 10; Outdoor Weathering—36 months, see 6.4; Daytime
mentary Requirement S1), and
Luminance Factor—Table 2; Other requirements:When sheet-
5.1.7.3 Reboundable sheeting requirements (see Supple-
ing is specified for construction work zone applications, the
mentary Requirement S2),
outdoor weathering shall be twelve months.
5.1.8 Indication that the sheeting is intended for work zone
use,ifapplicable,todeterminewhichweatheringrequirements
apply, and
5.1.9 Any additional information.
A
TABLE 1 Type I Sheeting
Observation Entrance
6. Performance Requirements White Yellow Orange Green Red Blue Brown
Angle Angle
6.1 This is a summary of the minimum performance re- 0.2° −4° 70 50 25 9.0 14 4.0 1.0
0.2° +30° 30 22 7.0 3.5 6.0 1.7 0.3
quirements for each type of retroreflective sheeting.
0.5° −4° 30 25 13 4.5 7.5 2.0 0.3
0.5° +30° 15 13 4.0 2.2 3.0 0.8 0.2
NOTE 2—The 0.1° observation angle supplementary R requirements
A
A 2 −1 −2
previously listed in this section have been moved to Appendix X3 to
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
highlight their optional nature.
D4956−19
A
TABLE 2 Daytime Luminance Factor (Y %) NOTE 3—Supplementary Requirement S3 describes a method for
artificial accelerated weathering, which users of this specification may
All except
Type V
employ for preliminary judgment until outdoor weathering results are
Type V
Color
available.
Minimum Maximum Minimum Maximum
White 27 . 15 6.5 Colorfastness—After the specified outdoor weathering,
Yellow 15 45 12 30
the specimen shall conform to the requirements of Table 2 and
Orange 10 30 7.0 25
Table 11 when tested in accordance with 7.4 and 7.7.
Green 3.0 12 2.5 11
Red 2.5 15 2.5 11
6.6 Shrinkage—The retroreflective sheeting shall not shrink
Blue 1.0 10 1.0 10
inanydimensionmorethan ⁄32in.(0.8mm)in10minormore
Purple 2.0 10 2.0 10
Brown 1.0 9.0 1.0 9.0
than ⁄8 in. (3.2 mm) in 24 h when tested in accordance with
Fluorescent Yellow-Green 60
7.8.
Fluorescent Yellow 40
Fluorescent Orange 20
6.7 Flexibility—The sheeting shall be sufficiently flexible to
Fluorescent Pink 25 .
show no cracking when tested in accordance with 7.9.
A
The luminance factors shown for fluorescent colors consist of the sum of a
reflectance luminance factor and fluorescence luminance factor. The luminance 6.8 Liner Removal—The liner, when provided, shall be
factor may be determined using a good approximation to Illuminant D65, requiring
easilyremovedwithoutsoakinginwaterorothersolutions,and
an instrument with an appropriately filtered light source, or by using a bispectral
shall not break, tear, or remove adhesive from the sheeting.
photometer conforming to Practice E2153.
(See 7.10.)
6.9 Adhesion—When tested in accordance with 7.5, the
A
TABLE 3 Type II Sheeting
adhesivebackingoftheretroreflectivesheetingshallproducea
Observation Entrance
White Yellow Orange Green Red Blue Brown bond that will support a 1 ⁄4-lb (0.79-kg) weight for adhesive
Angle Angle
classes1,2,and3ora1-lb(0.45-kg)weightforadhesiveclass
0.2° −4° 140 100 60 30 30 10 5.0
4 for 5 min, without the bond peeling for a distance of more
0.2° +30° 60 36 22 10 12 4.0 2.0
0.5° −4° 50 33 20 9.0 10 3.0 2.0
than 2 in. (51 mm).
0.5° +30° 28 20 12 6.0 6.0 2.0 1.0
6.10 Impact Resistance—Retroreflective sheeting shall
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
show no cracking or delamination outside of the actual area of
impact when subjected to the impact test in accordance with
A
7.11.
TABLE 4 Type III Sheeting
Observation Entrance
6.11 Nighttime Color—The nighttime color of the sheeting
White Yellow Orange Green Red Blue Brown
Angle Angle
shall conform to the requirements of Table 13, when tested in
0.2° −4° 250 170 100 45 45 20 12
accordance with 7.12.
0.2° +30° 150 100 60 25 25 11 8.5
0.5° −4° 95 62 30 15 15 7.5 5.0
0.5° +30° 65 45 25 10 10 5.0 3.5
7. Test Methods
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
7.1 Test Conditions—Unless otherwise specified in this
specification, condition all adhesively bonded and unbonded
6.2 CoeffıcientofRetroreflection—Thecoefficientofretrore- test samples and specimens at a temperature of 73 6 3°F (23
6 2°C) and 50 6 5% relative humidity for 24 h prior to
flectionshallmeetorexceedtheminimumrequirementsforthe
appropriate type of sheeting (see Table 1 and Tables 3-10)as testing.
specified in 7.3.
7.2 Panel Preparations—Unless otherwise specified in this
6.3 Daytime Color—Thecolorofthesheetingshallconform specification, when tests are to be performed using test panels,
apply the specimens of retroreflective material to smooth
to requirements of Table 2 and Table 11 when tested in
accordance with 7.4. Daytime color requirements were devel- aluminumcutfromAlloy6061-T6or5052-H38,inaccordance
with Specification B209 or B209M. The sheets shall be
oped for a limited set of retroreflective sheetings and a limited
set of measurement devices. Measurement techniques appro- 0.020in. (0.508 mm), 0.040 in. (1.016 mm), or 0.063 in.
priateforawiderrangeofopticaltechnologiesandinstruments (1.600mm) in thickness, and a minimum of 8 by 8 in. (200 by
are under development. Some sheeting may require visual 200mm). Prepare the aluminum in accordance with Specifi-
assessment to determine the acceptability of daytime appear- cation B449, Class 2, or degrease and lightly acid etch before
ance. thespecimensareapplied.Applythespecimenstothepanelsin
accordance with the recommendations of the retroreflective
6.4 Accelerated Outdoor Weathering Requirements—The
sheeting manufacturer.
retroreflective sheeting shall be weather resistant and show no
appreciable cracking, scaling, pitting, blistering, edge lifting, 7.3 Coeffıcient of Retroreflection:
or curling, or more than ⁄32-in. (0.8-mm) shrinkage or expan- 7.3.1 For lots, rolls, or sheets of retroreflective sheeting at
sion when tested in accordance with 7.6. Conduct retroreflec- least 1 yd long in new (unexposed) condition, take three
tivity measurements after outdoor weathering at 0.2° observa- samples in accordance with 9.1. Determine the coefficients of
tion and −4° and +30° entrance angles. The minimum retroreflection in accordance with Test Method E810.
coefficient of retroreflection (R ) after weathering is specified 7.3.1.1 To conform to this specification, the average of the
A
in Table 12. three coefficients of retroreflection shall meet the minimum
D4956−19
A
TABLE 5 Type IV Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple Brown
Angle Angle Yellow-Green Yellow Orange
0.20° −4° 360 270 145 50 65 30 14 18 290 220 105
0.20° +30° 170 135 68 25 30 14 6.8 8.5 135 100 50
0.50° −4° 150 110 60 21 27 13 6.0 7.5 120 90 45
0.50° +30° 72 54 28 10 13 6 2.9 3.5 55 40 22
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
A
TABLE 6 Type V Sheeting
an annular measurement. The number depends on the optical
Observation Entrance
construction of the specimen and must be determined by the
White Yellow Orange Green Red Blue Purple
Angle Angle
testing laboratory.
0.20° −4° 700 470 280 120 120 56 28
7.4.3 Instruments (spectrophotometers, colorimeters) used
0.20° +30° 400 270 160 72 72 32 16
to measure daytime color shall have 45/0 or 0/45 illumination
0.50° −4° 160 110 64 28 28 13 6.4
0.50° +30° 75 51 30 13 13 6.0 3.0
and viewing geometry. The referee instrument shall have 10°
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
apertures for both illumination and viewing. Use of aperture
A
sizes deviating from these may affect the measurement results.
7.5 Adhesion—Apply the sheeting to a test panel, 0.040 in.
(1.016 mm) minimum thickness, prepared as specified in 7.2.
Bond 4 in. (102 mm) ofa1by 6-in. (25.4 by 152-mm)
limits given in 6.2 and none of the coefficients of retroreflec-
specimentoatestpanel.Condition(see7.1)andthenattachthe
tion obtained on any of the samples shall be less than 80% of
weight to the free end and allow it to hang free at an angle of
the values required in 6.2.
90° to the panel surface for 5 min.
7.4 Daytime Color:
7.6 Outdoor Weathering—Conduct outdoor exposures in
7.4.1 Determine the chromaticity and luminance factor Y
accordance with Practice G7/G7M. During exposure, test
(%) for CIE standard illuminant D65 and the 1931 CIE 2°
panels shall be open backed and oriented at an angle of 45°
standard observer in accordance with Practice E308, Test
from the horizontal and facing the equator in accordance with
Methods E1347, E1349, and E2301, and Practices E991,
Practice G7/G7M. Expose two panels per location for the
E1164,E2152,andE2153,asapplicable.Theluminancefactor
number of months specified in Table 12. Conduct exposures in
is the sum of the reflectance luminance factor and the fluores-
locations with the climate types shown in Table 14. Panel
cence luminance factor. Bispectral measurement provides the
labeling, and conditioning and handling of panels prior to
individual factors, while measurement with simulated D65
exposure and during evaluation periods shall be in accordance
provides their sum.
with Practice G147.
7.4.1.1 For fluorescent specimens, it is necessary either that
7.6.1 Specimen Mounting for Type VI Sheetings—Clampthe
the physical illumination of the specimen be a good approxi-
ends of 4 by 12-in. (100 by 300-mm) specimens between 1 by
mation to illuminant D65, requiring an instrument with an
8by ⁄64-in.(25by200by2-mm)6061-T6aluminumbars,and
appropriately filtered light source, or else that a bispectral
attach these bars to mounting strips on the outdoor exposure
photometer conforming to Test Method E2301 be used. The
rack. Expose the specimens so that the long axis is parallel to
presence of fluorescence may be determined through use of
the ground so that bolts used to clamp specimen ends do not
Practice E1247.
interfere with attachment to the test rack. Fig. 2 is a diagram
7.4.2 There are three types of 45/0 (0/45) instruments:
showing the arrangement of the clamping bars and the test
annular, circumferential, and uniplanar (see Fig. 1). Measure-
specimen.
ment of prismatic sheeting with circumferential instruments
7.6.2 Washing Panels After Exposure—Following exposure,
mayrequiremultiplemeasurements.Measurementofprismatic
gently wash the panels using a soft cloth or sponge and clean
sheeting with uniplanar instruments definitely requires mul-
wateroradilutesolutionofamilddetergent(1%byweightin
tiple measurements.
water, maximum concentration). After washing, rinse thor-
7.4.2.1 If the measurement geometry is circumferential,
oughly with clean water, and blot dry with a soft, clean cloth.
then the testing laboratory must verify that the apertures in the
After washing and drying, condition the panels at room
ring are sufficiently close for acceptable approximation to an
temperature for at least 2 h prior to conducting any property
annular measurement. This may depend on the optical con-
measurements.
struction of the specimen, and must be determined by the
7.6.3 Measurement of Coeffıcient of Retroreflection—After
testing laboratory. Multiple measurements of the same speci-
panelshavebeenwashed,dried,andconditionedinaccordance
men area at different rotations may be averaged to improve the
with 7.6.2, measure retroreflectance at 0.2° observation and
approximation to an annular measurement.
–4° and 30° entrance angles. Report the average of the
7.4.2.2 If the measurement geometry is uniplanar, then a
coefficient of retroreflection measured at each geometry on the
sequence of measurements shall be made on the same speci-
two panels from each exposure location.
men area at incrementalrotations,andthemeasurementvalues
shallbetakenasaveragesoveralltherotations.Thenumberof
NOTE 4—The use of two samples per weathering deck is considered a
rotationsshallbelargeenoughforacceptableapproximationto minimum and reflects historical practice and practicality. Additional
D4956−19
A
TABLE 7 Type VI Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple
Angle Angle Yellow-Green Yellow Orange Pink
0.20° −4° 500 350 125 60 70 45 20 400 300 200 150
0.20° +30° 200 140 50 24 28 18 8.0 160 120 80 60
0.50° −4° 225 160 56 27 32 20 9.0 180 135 90 65
0.50° +30° 85 60 21 10 12 7.7 3.4 68 51 34 25
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
A
TABLE 8 Type VIII Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple Brown
Angle Angle Yellow-Green Yellow Orange
0.20° −4° 700 525 265 70 105 32 28 21 560 420 210
0.20° +30° 325 245 120 33 49 15 13 10 260 200 95
0.50° −4° 250 190 94 25 38 11 10 7.5 200 150 75
0.50° +30° 115 86 43 12 17 5.0 4.6 3.5 92 69 35
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
A
TABLE 9 Type IX Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple
Angle Angle Yellow-Green Yellow Orange
0.20° − 4° 380 285 145 38 76 17 15 300 230 115
0.20° +30° 215 162 82 22 43 10 8.6 170 130 65
0.50° −4° 240 180 90 24 48 11 10 190 145 72
0.50° +30° 135 100 50 14 27 6.0 5.4 110 81 41
1.00° −4° 80 60 30 8.0 16 3.6 3.2 64 48 24
1.00° +30° 45 34 17 4.5 9.0 2.0 1.8 36 27 14
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
A
TABLE 10 Type XI Sheeting
Observation Entrance White Yellow Orange Green Red Blue Purple Brown Fluorescent Fluorescent Fluorescent
Angle Angle Yellow-Green Yellow Orange
0.20° −4° 580 435 200 58 87 26 23 17 460 350 175
0.20° +30° 220 165 77 22 33 10 8.8 7.0 180 130 66
0.50° −4° 420 315 150 42 63 19 17 13 340 250 125
0.50° +30° 150 110 53 15 23 7.0 6.0 5.0 120 90 45
1.00° −4° 120 90 42 12 18 5.0 4.8 4.0 96 72 36
1.00° +30° 45 34 16 5.0 7.0 2.0 1.8 1.0 36 27 14
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
samples may be weathered, and the results averaged, to decrease the
prevent sticking to the mandrel.The test specimen shall be 2 ⁄4
effects of variability associated with the weathering process.
by 11 in. (70 by 229 mm). The test temperature shall be 73 6
NOTE 5—Weathering tests are generally performed less frequently than
3°F (23 6 2°C).
other tests in this specification. Judgment must be used to satisfy the user
that weathering results obtained on exposed samples are sufficiently
7.10 Liner Removal—The protective liner, if any, shall be
applicable to the material being supplied.
easily removed following accelerated storage for4hat160°F
7.7 Colorfastness—Useoneoftheoutdoor-weatheredspeci-
(71°C) under a weight of 2.5 psi (17.2 kPa).
mens to test for colorfastness. Wash, dry, and condition panels
7.11 Impact Resistance—Apply the retroreflective sheeting
in accordance with 7.6.2 and test as specified in 7.4.
toa3by5by 0.040-in. (76 by 127 by 1.016-mm) 6061-T6
7.8 Shrinkage—Conditiona9by 9-in. (229 by 229-mm)
aluminum test panel as specified in 7.2 and test condition as
retroreflective sheeting specimen with liner, a minimum of 1 h
specified in 7.1. Utilizing the test instrument and procedures
at standard test conditions (see 7.1). Remove the liner and
described in Test Method D2794, subject the sheeting to the
place the specimen on a flat surface with the adhesive side up.
impact of a 2-lb (0.91-kg) weight dropped from the height
Ten minutes after the liner is removed and again after 24 h,
necessary to generate an impact of 10 in.-lb (1.13 N-m) when
measure the specimen to determine the amount of dimensional
str
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4956 − 17 D4956 − 19
Standard Specification for
Retroreflective Sheeting for Traffic Control
This standard is issued under the fixed designation D4956; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers flexible, non-exposed glass bead glass-bead lens and microprismatic, retroreflective sheeting
designed for use on traffic control signs, delineators, barricades, and other devices. This specification does not address inks,
overlays, or other imaging methods that may be applied to retroreflective sheeting material to create traffic signs or other devices.
1.2 Although this specification provides photometric requirements for retroreflective sheeting under evaluation, minimum
performance requirements of in-service signs or other devices are outside the scope of this document.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.4 The following safety hazards caveat pertains only to the test methods portion, Section 7, of this specification. This standard
does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this
standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory
limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
B209 Specification for Aluminum and Aluminum-Alloy Sheet and Plate
B209M Specification for Aluminum and Aluminum-Alloy Sheet and Plate (Metric)
B449 Specification for Chromates on Aluminum
D2794 Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact)
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
E808 Practice for Describing Retroreflection
E810 Test Method for Coefficient of Retroreflection of Retroreflective Sheeting Utilizing the Coplanar Geometry
E811 Practice for Measuring Colorimetric Characteristics of Retroreflectors Under Nighttime Conditions
E991 Practice for Color Measurement of Fluorescent Specimens Using the One-Monochromator Method
E1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation
E1247 Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
E1349 Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45°:0° or 0°:45°) Geometry
E2152 Practice for Computing the Colors of Fluorescent Objects from Bispectral Photometric Data
E2153 Practice for Obtaining Bispectral Photometric Data for Evaluation of Fluorescent Color
E2301 Test Method for Daytime Colorimetric Properties of Fluorescent Retroreflective Sheeting and Marking Materials for High
Visibility Traffic Control and Personal Safety Applications Using 45°:Normal Geometry
This specification is under the jurisdiction of ASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.38 on Highway
Traffic Control Materials.
Current edition approved Oct. 1, 2017July 1, 2019. Published October 2017July 2019. Originally approved in 1989. Last previous edition approved in 20162017 as
D4956 – 16b.D4956 – 17. DOI: 10.1520/D4956-17.10.1520/D4956-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4956 − 19
E3165 Test Method for Nighttime Retroreflected Chromaticity of Retroreflective Sheeting
G7G7/G7M Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G155 Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials
2.2 Other StandardsStandards:
ISO 4892-2:2006 Plastics MethodsPlastics—Methods of exposure to laboratory light sources - Part 2: Xenon-arc lampsExposure
to Laboratory Light Sources—Part 2: Xenon-Arc Lamps
ISO 4892-2:2006/Amd.1:2009 Plastics MethodsPlastics—Methods of exposure to laboratory light sources - Part 2: Xenon-arc
lampsExposure to Laboratory Light Sources—Part 2: Xenon-Arc Lamps
EN12899-1:2007 EN 12899-1:2007 Fixed, vertical road traffic signs - Part Vertical Road Traffic Signs—Part 1: Fixed
signsSigns
3. Terminology
3.1 Definitions—Definitions of terms are as described in Terminology E284, Practice E808, and Terminology G113.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 reboundable sheeting, n—retroreflective material intended to be attached to flexible, impact-resistant plastic devices, such
as traffic drum-like channelizing devices.
4. Classification
4.1 Retroreflective sheeting shall consist of a white or colored sheeting having a smooth outer surface and that essentially has
the property of a retroreflector over its entire surface. There are nine types and five classes of retroreflective sheeting. Types are
determined by conformance to the retroreflectance, color, and durability requirements listed in 6.1 and may be of any construction
providing that those requirements are met. Type designation is provided as a means for differentiating functional performance.
Typical examples of applications are provided for descriptive information only and are not intended to be limitations or
recommendations. Common identifiers for each type are listed in 4.2.
4.1.1 The typical applications for the retroreflective sheeting addressed in this specification are:
Type Typical Application
I Highway signing, construction-zone devices, and delineators
II Highway signing, construction-zone devices, and delineators
III Highway signing, construction-zone devices, and delineators
IV Highway signing, construction-zone devices, and delineators
V Delineators
VI Temporary roll-up signs, warning signs, traffic cone collars, and post
bands
VII This type designation has been replaced with Type VIII
VIII Highway signing, construction-zone devices, and delineators
IX Highway signing, construction-zone devices, and delineators
X This type designation has been replaced with Type VIII
XI Highway signing, construction-zone devices, and delineators
4.2 Retroreflective sheeting shall be classified as follows (the type sequence is not indicative of performance level):
4.2.1 Type I—A retroreflective sheeting referred to as “engineering grade” that is typically an enclosed lens glass-bead sheeting.
retroreflective material or a microprismatic retroreflective element material. Applications for this material include permanent
highway signing, construction zone devices, and delineators.
4.2.2 Type II—A retroreflective sheeting referred to as “super engineer grade” that is typically an enclosed lens glass-bead
sheeting. retroreflective material or a microprismatic retroreflective element material. Applications for this material include
permanent highway signing, construction zone devices, and delineators.
4.2.3 Type III—A retroreflective sheeting referred to as “high-intensity” that is typically manufactured as an encapsulated
glass-bead retroreflective material or as an unmetalized a microprismatic retroreflective element material. Applications for this
material include permanent highway signing, construction zone devices, and delineators.
4.2.4 Type IV—A retroreflective sheeting referred to as “high-intensity” that is typically an unmetalized microprismatic
retroreflective element material. Applications for this material include permanent highway signing, construction zone devices, and
delineators.
4.2.5 Type V—A retroreflective sheeting referred to as “super high-intensity” that is typically a metalized microprismatic
retroreflective element material. This sheeting is typically used for delineators.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
Available from European Committee for Standardization (CEN), Avenue Marnix 17, B-1000, Brussels, Belgium, http://www.cen.eu.
D4956 − 19
4.2.6 Type VI—An elastomeric retroreflective sheeting without adhesive. This sheeting is typically a vinyl microprismatic
retroreflective material. Applications include orange temporary roll-up warning signs, traffic cone collars, and post bands.
4.2.7 Type VII—Retroreflective sheeting materials previously classified as Type VII have been reclassified as Type VIII. The use
of a designation as Type VII has been discontinued.
4.2.8 Type VIII—A retroreflective sheeting typically manufactured as an unmetalized cube corner microprismatic retroreflective
element material. Applications for this material include permanent highway signing, construction zone devices, and delineators.
4.2.9 Type IX—A retroreflective sheeting typically manufactured as an unmetalized cube corner microprismatic retroreflective
element material. Applications for this material include permanent highway signing, construction zone devices, and delineators.
4.2.10 Type X—Retroreflective sheeting materials previously classified as Type X have been reclassified as Type VIII. The use
of a designation as Type X has been discontinued.
4.2.11 Type XI—A retroreflective sheeting typically manufactured as an unmetalized cube corner microprismatic retroreflective
element material. Applications for this material include permanent highway signing, construction zone devices, and delineators.
NOTE 1—All retroreflective sheetings, but especially microprismatic sheetings, may have unique performance characteristics outside of the range of
the standard geometries presented in the tables that define the types. Certain applications may require the use of a particular product within a particular
type in order to achieve a desired level of retroreflectivity in a given situation. In these cases, information concerning additional performance
characteristics must be obtained.
4.3 Backing Classes—The backing required for retroreflective sheeting shall be classified as follows:
4.3.1 Class 1—The adhesive backing shall be pressure sensitive, require no heat, solvent, or other preparation for adhesion to
smooth, clean surfaces.
4.3.2 Class 2—The adhesive backing shall have an adhesive that shall be activated by applying heat and pressure to the material.
The temperature necessary to form a durable permanent bond shall be a minimum of 150 °F (66 °C).
4.3.2.1 The Class 2 material shall be repositionable under normal shop conditions and at substrate temperatures up to 100 °F
(38 °C) and without damage to the material. The Class 2 material may be perforated to facilitate removal of air in heat-vacuum
laminators, but the perforations must be of a size and frequency such that they do not cause objectionable blemishes when the
sheeting is printed.
4.3.3 Class 3—The adhesive backing shall have a positionable, low-tack, pressure-sensitive adhesive that requires no heat,
solvent, or other preparation for adhesion to smooth, clean surfaces. It shall be repositionable up to a temperature of 100 °F (38 °C)
without damage to the material.
4.3.4 Class 4—The adhesive backing shall have a low-temperature, pressure-sensitive adhesive that permits sheeting
applications at temperatures down to +20 °F (−7 °C) without the aid of heat, solvent, or other preparation for adhesion to smooth,
dry, clean surfaces.
4.3.5 Class 5—This shall be a nonadhesive backing made of material commercially used for self-supporting products such as
traffic cone collars, temporary roll-up warning signs, and post bands.
5. Ordering Information
5.1 The purchaser using this specification shall include the following information:
5.1.1 ASTM designation (D4956),
5.1.2 Classification type (see Section 4),
5.1.3 Adhesive class (see 4.3),
5.1.4 Daytime color (see 6.3),
5.1.5 Length and width of sheets (see 8.1),
5.1.6 Length and width of rolls (see 8.2),
5.1.7 Supplementary information, if required by the purchaser, including:
5.1.7.1 Compliance with the minimum coefficient of retroreflection for 0.1° observation angle is a supplementary requirement
which shall apply only when specified. An observation angle of 0.1° may be specified where the long distance long-distance
performance of a sheeting is to be a requirement,
5.1.7.2 Fungus-resistance testing requirements (see Supplementary Requirement S1), and
5.1.7.3 Reboundable sheeting requirements (see Supplementary Requirement S2),
5.1.8 Indication that the sheeting is intended for work zone use, if applicable, to determine which weathering requirements
apply, and
5.1.9 Any additional information.
6. Performance Requirements
6.1 This is a summary of the minimum performance requirements for each type of retroreflective sheeting.
NOTE 2—The 0.1° observation angle supplementary R requirements previously listed in this section have been moved to Appendix X3 to highlight
A
their optional nature.
D4956 − 19
6.1.1 Type I—Minimum Coefficient of Retroreflection—Table 1; Outdoor Weathering—24 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.2 Type II—Minimum Coefficient of Retroreflection—Table 3; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.3 Type III—Minimum Coefficient of Retroreflection—Table 4; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.4 Type IV—Minimum Coefficient of Retroreflection—Table 5; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.5 Type V—Minimum Coefficient of Retroreflection—Table 6; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.6 Type VI—Minimum Coefficient of Retroreflection—Table 7; Outdoor Weathering—six months, see 6.4; Daytime
Luminance Factor—Table 2.
6.1.7 Type VII—Retroreflective sheeting materials previously classified as Type VII have been reclassified as Type VIII.
6.1.8 Type VIII—Minimum Coefficient of Retroreflection—Table 8; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.9 Type IX—Minimum Coefficient of Retroreflection—Table 9; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.1.10 Type X—Retroreflective sheeting materials previously classified as Type X have been reclassified as Type VIII.
6.1.11 Type XI—Minimum Coefficient of Retroreflection—Table 10; Outdoor Weathering—36 months, see 6.4; Daytime
Luminance Factor—Table 2; Other requirements: When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
6.2 Coeffıcient of Retroreflection—The coefficient of retroreflection shall meet or exceed the minimum requirements for the
appropriate type of sheeting (see Table 1 and Tables 3-10) as specified in 7.3.
6.3 Daytime Color—The color of the sheeting shall conform to requirements of Table 2 and Table 11 when tested in accordance
with 7.4. Daytime color requirements were developed for a limited set of retroreflective sheetings and a limited set of measurement
devices. Measurement techniques appropriate for a wider range of optical technologies and instruments are under development.
Some sheeting may require visual assessment to determine the acceptability of daytime appearance.
6.4 Accelerated Outdoor Weathering Requirements—The retroreflective sheeting shall be weather resistant and show no
appreciable cracking, scaling, pitting, blistering, edge lifting, or curling, or more than ⁄32-in. (0.8-mm) shrinkage or expansion
when tested in accordance with 7.6. Conduct retroreflectivity measurements after outdoor weathering at 0.2° observation and −4°
and +30° entrance angles. The minimum coefficient of retroreflection (R ) after weathering is specified in Table 12.
A
NOTE 3—Supplementary Requirement S3 describes a method for artificial accelerated weathering, which users of this specification may employ for
preliminary judgment until outdoor weathering results are available.
6.5 Colorfastness—After the specified outdoor weathering, the specimen shall conform to the requirements of Table 2 and Table
11 when tested in accordance with 7.4 and 7.7.
6.6 Shrinkage—The retroreflective sheeting shall not shrink in any dimension more than ⁄32 in. (0.8 mm) in 10 min or more
than ⁄8 in. (3.2 mm) in 24 h when tested in accordance with 7.8.
6.7 Flexibility—The sheeting shall be sufficiently flexible to show no cracking when tested in accordance with 7.9.
6.8 Liner Removal—The liner, when provided, shall be easily removed without soaking in water or other solutions, and shall
not break, tear, or remove adhesive from the sheeting. (See 7.10.)
A
TABLE 1 Type I Sheeting
Observation Entrance
White Yellow Orange Green Red Blue Brown
Angle Angle
0.2° −4° 70 50 25 9.0 14 4.0 1.0
0.2° +30° 30 22 7.0 3.5 6.0 1.7 0.3
0.5° −4° 30 25 13 4.5 7.5 2.0 0.3
0.5° +30° 15 13 4.0 2.2 3.0 0.8 0.2
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
D4956 − 19
A
TABLE 2 Daytime Luminance Factor (Y %) %)
All except
Type V
Type V
Color
Minimum Maximum Minimum Maximum
White 27 . 15
Yellow 15 45 12 30
Orange 10 30 7.0 25
Green 3.0 12 2.5 11
Red 2.5 15 2.5 11
Blue 1.0 10 1.0 10
Purple 2.0 10 2.0 10
Brown 1.0 9.0 1.0 9.0
Fluorescent Yellow-Green 60
Fluorescent Yellow 40
Fluorescent Orange 20
Fluorescent Pink 25 .
A
The luminance factors shown for fluorescent colors consist of the sum of a
reflectance luminance factor and fluorescence luminance factor. The luminance
factor may be determined using a good approximation to Illuminant D65, requiring
an instrument with an appropriately filtered light source, or by using a bispectral
photometer conforming to Test Method Practice G147E2153.
A
TABLE 3 Type II Sheeting
Observation Entrance
White Yellow Orange Green Red Blue Brown
Angle Angle
0.2° −4° 140 100 60 30 30 10 5.0
0.2° +30° 60 36 22 10 12 4.0 2.0
0.5° −4° 50 33 20 9.0 10 3.0 2.0
0.5° +30° 28 20 12 6.0 6.0 2.0 1.0
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
A
TABLE 4 Type III Sheeting
Observation Entrance
White Yellow Orange Green Red Blue Brown
Angle Angle
B
0.1° −4° 300 200 120 54 54 24 14
B
0.1° +30° 180 120 72 32 32 14 10
0.2° −4° 250 170 100 45 45 20 12
0.2° +30° 150 100 60 25 25 11 8.5
0.5° −4° 95 62 30 15 15 7.5 5.0
0.5° +30° 65 45 25 10 10 5.0 3.5
A
TABLE 4 Type III Sheeting
Observation Entrance
White Yellow Orange Green Red Blue Brown
Angle Angle
0.2° −4° 250 170 100 45 45 20 12
0.2° +30° 150 100 60 25 25 11 8.5
0.5° −4° 95 62 30 15 15 7.5 5.0
0.5° +30° 65 45 25 10 10 5.0 3.5
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angle are supplementary requirements that shall
apply only when specified by the purchaser in the contract or order.
6.9 Adhesion—When tested in accordance with 7.5, the adhesive backing of the retroreflective sheeting shall produce a bond
that will support a 1 ⁄4-lb (0.79-kg) weight for adhesive classes 1, 2, and 3 or a 1-lb (0.45-kg) weight for adhesive class 4 for 5
min, without the bond peeling for a distance of more than 2 in. (51 mm).
6.10 Impact Resistance—Retroreflective sheeting shall show no cracking or delamination outside of the actual area of impact
when subjected to the impact test in accordance with 7.11.
6.11 Nighttime Color—The nighttime color of the sheeting shall conform to the requirements of Table 13, when tested in
accordance with 7.12.
7. Test Methods
7.1 Test Conditions—Unless otherwise specified in this specification, condition all adhesively bonded and unbonded test
samples and specimens at a temperature of 73 6 3 °F (23 6 2 °C) and 50 6 5 % relative humidity for 24 h prior to testing.
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A
TABLE 5 Type IV Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple Brown
Angle Angle Yellow-Green Yellow Orange
B
0.10° −4° 500 380 200 70 90 42 20 25 400 300 150
B
0.10° +30° 240 175 94 32 42 20 10 12 185 140 70
0.20° −4° 360 270 145 50 65 30 14 18 290 220 105
0.20° +30° 170 135 68 25 30 14 6.8 8.5 135 100 50
0.50° −4° 150 110 60 21 27 13 6.0 7.5 120 90 45
0.50° +30° 72 54 28 10 13 6 2.9 3.5 55 40 22
A
TABLE 5 Type IV Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple Brown
Angle Angle Yellow-Green Yellow Orange
0.20° −4° 360 270 145 50 65 30 14 18 290 220 105
0.20° +30° 170 135 68 25 30 14 6.8 8.5 135 100 50
0.50° −4° 150 110 60 21 27 13 6.0 7.5 120 90 45
0.50° +30° 72 54 28 10 13 6 2.9 3.5 55 40 22
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angle are supplementary requirements that shall apply only when specified by the purchaser in the contract or order.
A
TABLE 6 Type V Sheeting
Observation Entrance
White Yellow Orange Green Red Blue Purple
Angle Angle
B
0.10° −4° 2000 1300 800 360 360 160 80
B
0.10° +30° 1100 740 440 200 200 88 45
0.20° −4° 700 470 280 120 120 56 28
0.20° +30° 400 270 160 72 72 32 16
0.50° −4° 160 110 64 28 28 13 6.4
0.50° +30° 75 51 30 13 13 6.0 3.0
A
TABLE 6 Type V Sheeting
Observation Entrance
White Yellow Orange Green Red Blue Purple
Angle Angle
0.20° −4° 700 470 280 120 120 56 28
0.20° +30° 400 270 160 72 72 32 16
0.50° −4° 160 110 64 28 28 13 6.4
0.50° +30° 75 51 30 13 13 6.0 3.0
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angle are supplementary requirements that shall
apply only when specified by the purchaser in the contract or order.
7.2 Panel Preparations—Unless otherwise specified in this specification, when tests are to be performed using test panels, apply
the specimens of retroreflective material to smooth aluminum cut from Alloy 6061-T6 or 5052-H38, in accordance with
Specification B209 or B209M. The sheets shall be 0.020 in. (0.508 mm), 0.040 in. (1.016 mm), or 0.063 in. (1.600 mm) in
thickness, and a minimum of 8 by 8 in. (200 by 200 mm). Prepare the aluminum in accordance with Specification B449, Class 2,
or degrease and lightly acid etch before the specimens are applied. Apply the specimens to the panels in accordance with the
recommendations of the retroreflective sheeting manufacturer.
7.3 Coeffıcient of Retroreflection:
7.3.1 For lots, rolls, or sheets of retroreflective sheeting at least 1 yd long in new (unexposed) condition, take three samples in
accordance with 9.1. Determine the coefficients of retroreflection in accordance with Test Method E810.
7.3.1.1 To conform to this specification, the average of the three coefficients of retroreflection shall meet the minimum limits
given in 6.2 and none of the coefficients of retroreflection obtained on any of the samples shall be less than 80 % of the values
required in 6.2.
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A
TABLE 7 Type VI Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple
Angle Angle Yellow-Green Yellow Orange Pink
B
0.10° −4° 750 525 190 90 105 68 30 600 450 300 225
B
0.10° +30° 300 210 75 36 42 27 12 240 180 120 90
0.20° −4° 500 350 125 60 70 45 20 400 300 200 150
0.20° +30° 200 140 50 24 28 18 8.0 160 120 80 60
0.50° −4° 225 160 56 27 32 20 9.0 180 135 90 65
0.50° +30° 85 60 21 10 12 7.7 3.4 68 51 34 25
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angle are supplementary requirements that shall apply only when specified by the purchaser in the contract or order.
A
TABLE 8 Type VIII Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple Brown
Angle Angle Yellow-Green Yellow Orange
B
0.10° −4° 1000 750 375 100 150 45 40 30 800 600 300
B
0.10° +30° 460 345 175 46 69 21 18 14 370 280 135
0.20° −4° 700 525 265 70 105 32 28 21 560 420 210
0.20° +30° 325 245 120 33 49 15 13 10 260 200 95
0.50° −4° 250 190 94 25 38 11 10 7.5 200 150 75
0.50° +30° 115 86 43 12 17 5.0 4.6 3.5 92 69 35
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angle are supplementary requirements that shall apply only when specified by the purchaser in the contract or order.
A
TABLE 9 Type IX Sheeting
Observation Entrance Fluorescent Fluorescent Fluorescent
White Yellow Orange Green Red Blue Purple
Angle Angle Yellow-Green Yellow Orange
B
0.10° −4° 660 500 250 66 130 30 26 530 400 200
B
0.10° +30° 370 280 140 37 74 17 15 300 220 110
0.20° − 4° 380 285 145 38 76 17 15 300 230 115
0.20° +30° 215 162 82 22 43 10 8.6 170 130 65
0.50° −4° 240 180 90 24 48 11 10 190 145 72
0.50° +30° 135 100 50 14 27 6.0 5.4 110 81 41
1.00° −4° 80 60 30 8.0 16 3.6 3.2 64 48 24
1.00° +30° 45 34 17 4.5 9.0 2.0 1.8 36 27 14
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angles are supplementary requirements that shall apply only when specified by the purchaser in the contract or order.
A
TABLE 10 Type XI Sheeting
Observation Entrance White Yellow Orange Green Red Blue Purple Brown Fluorescent Fluorescent Fluorescent
Angle Angle Yellow-Green Yellow Orange
B
0.10° −4° 830 620 290 83 125 37 33 25 660 500 250
B
0.10° +30° 325 245 115 33 50 15 13 10 260 200 100
0.20° −4° 580 435 200 58 87 26 23 17 460 350 175
0.20° +30° 220 165 77 22 33 10 8.8 7.0 180 130 66
0.50° −4° 420 315 150 42 63 19 17 13 340 250 125
0.50° +30° 150 110 53 15 23 7.0 6.0 5.0 120 90 45
1.00° −4° 120 90 42 12 18 5.0 4.8 4.0 96 72 36
1.00° +30° 45 34 16 5.0 7.0 2.0 1.8 1.0 36 27 14
A 2 −1 −2
Minimum Coefficient of Retroreflection (R ) cd/fc/ft (cd·lx ·m ).
A
B
Values for 0.1° observation angle are supplementary requirements that shall only apply when specified by the purchaser in the contract or order.
7.4 Daytime Color:
7.4.1 Determine the chromaticity and luminance factor Y(%)Y (%) for CIE standard illuminant D65 and the 1931 CIE 2°
standard observer in accordance with Practice E308, Test Methods E1347, E1349, and E2301, and Practices E991, E1164, E2152,
and E2153, as applicable. The luminance factor is the sum of the reflectance luminance factor and the fluorescence luminance
factor. Bispectral measurement provides the individual factors, while measurement with simulated D65 provides their sum.
7.4.1.1 For fluorescent specimens, it is necessary either that the physical illumination of the specimen be a good approximation
to illuminant D65, requiring an instrument with an appropriately filtered light source, or else that a bispectral photometer
conforming to Test Method E2301 be used. The presence of fluorescence may be determined through use of Practice E1247.
7.4.2 There are three types of 45/0 (0/45) instruments: annular, circumferential, and uniplanar (see Fig. 1). Measurement of
prismatic sheeting with circumferential instruments may require multiple measurements. Measurement of prismatic sheeting with
uniplanar instruments definitely requires multiple measurements.
D4956 − 19
A
TABLE 11 Color Specification Limits (Daytime)
1 2 3 4 5
Color
x y x y x y x y x y
White 0.303 0.300 0.368 0.366 0.340 0.393 0.274 0.329
Yellow 0.498 0.412 0.557 0.442 0.479 0.520 0.438 0.472
Orange 0.558 0.352 0.636 0.364 0.570 0.429 0.506 0.404
B
Green 0.026 0.399 0.166 0.364 0.286 0.446 0.207 0.771
Red 0.648 0.351 0.735 0.265 0.629 0.281 0.565 0.346
Red 0.565 0.346 0.629 0.281 0.735 0.265 0.648 0.351
B
Blue 0.140 0.035 0.244 0.210 0.190 0.255 0.065 0.216
Purple 0.302 0.064 0.310 0.210 0.380 0.255 0.468 0.140
Purple 0.302 0.064 0.468 0.140 0.380 0.255 0.310 0.210
Brown 0.430 0.340 0.610 0.390 0.550 0.450 0.430 0.390
Fluorescent Yellow-Green0.387 0.610 0.369 0.546 0.428 0.496 0.460 0.540
Fluorescent Yellow 0.479 0.520 0.446 0.483 0.512 0.421 0.557 0.442
Fluorescent Orange 0.583 0.416 0.535 0.400 0.595 0.351 0.645 0.355
Fluorescent Pink 0.600 0.340 0.450 0.332 0.430 0.275 0.536 0.230 0.644 0.290
A
The four pairs (five pairs for fluorescent pink) of chromaticity coordinates determine the acceptable color in terms of the CIE 1931 Standard Colorimetric System
measured with CIE Standard Illuminant D65.
B
The saturation limit of green and blue may extend to the border of the CIE chromaticity locus for spectral colors.
TABLE 12 Outdoor Weathering Photometric Requirements for All
Climates
Minimum Coefficient of
A
Type Months
Retroreflection, R
A
B
I 24 50 % of Table 1
B
II 36 65 % of Table 3
B
III 36 80 % of Table 4
B
IV 36 80 % of Table 5
B
V 36 80 % of Table 6
VI 6 50 % of Table 7
B
VIII 36 80 % of Table 8
B
IX 36 80 % of Table 9
B
XI 36 80 % of Table 10
A
Testing at shorter intervals may be done to gather additional information.
B
When sheeting is specified for construction work zone applications, the outdoor
weathering shall be twelve months.
7.4.2.1 If the measurement geometry is circumferential, then the testing laboratory must verify that the apertures in the ring are
sufficiently close for acceptable approximation to an annular measurement. This may depend on the optical construction of the
specimen, and must be determined by the testing laboratory. Multiple measurements of the same specimen area at different
rotations may be averaged to improve the approximation to an annular measurement.
7.4.2.2 If the measurement geometry is uniplanar, then a sequence of measurements shall be made on the same specimen area
at incremental rotations, and the measurement values shall be taken as averages over all the rotations. The number of rotations shall
be large enough for acceptable approximation to an annular measurement. The number depends on the optical construction of the
specimen and must be determined by the testing laboratory.
7.4.3 Instruments (spectrophotometers, colorimeters) used to measure daytime color shall have 45/0 or 0/45 illumination and
viewing geometry. The referee instrument shall have 10° apertures for both illumination and viewing. Use of aperture sizes
deviating from these may affect the measurement results.
7.5 Adhesion—Apply the sheeting to a test panel, 0.040 in. (1.016 mm) minimum thickness, prepared as specified in 7.2. Bond
4 in. (102 mm) of a 1 by 6-in. (25.4 by 152-mm) specimen to a test panel. Condition (see 7.1) and then attach the weight to the
free end and allow it to hang free at an angle of 90° to the panel surface for 5 min.
7.6 Outdoor Weathering—Conduct outdoor exposures in accordance with Practice G7G7/G7M. During exposure, test panels
shall be open backed and oriented at an angle of 45° from the horizontal and facing the equator in accordance with Practice
G7G7/G7M. Expose two panels per location for the number of months specified in Table 12. Conduct exposures in locations with
the climate types shown in Table 14. Panel labeling, and conditioning and handling of panels prior to exposure and during
evaluation periods shall be in accordance with Practice G147.
7.6.1 Specimen Mounting for Type VI Sheetings—Clamp the ends of 4 by 12-in. (100 by 300-mm) specimens between 1 by 8
by ⁄64-in. (25 by 200 by 2-mm) 6061-T6 aluminum bars, and attach these bars to mounting strips on the outdoor exposure rack.
Expose the specimens so that the long axis is parallel to the ground so that bolts used to clamp specimen ends do not interfere with
attachment to the test rack. Fig. 2 is a diagram showing the arrangement of the clamping bars and the test specimen.
D4956 − 19
A
TABLE 13 Color Specification Limits (Nighttime)
Color 1 2 3 4
x y x y x y x y
White 0.475 0.452 0.360 0.415 0.392 0.370 0.515 0.409
Yellow 0.513 0.487 0.500 0.470 0.545 0.425 0.572 0.425
Orange 0.595 0.405 0.565 0.405 0.613 0.355 0.643 0.355
Green 0.007 0.570 0.200 0.500 0.322 0.590 0.193 0.782
Red 0.650 0.348 0.620 0.348 0.712 0.255 0.735 0.265
Blue 0.033 0.370 0.180 0.370 0.230 0.240 0.091 0.133
Blue 0.091 0.133 0.230 0.240 0.180 0.370 0.033 0.370
Purple 0.355 0.088 0.385 0.288 0.500 0.350 0.635 0.221
Purple 0.355 0.088 0.635 0.221 0.500 0.350 0.385 0.288
Brown 0.595 0.405 0.540 0.405 0.570 0.365 0.643 0.355
Fluorescent Yellow-Green 0.480 0.520 0.473 0.490 0.523 0.440 0.550 0.449
Fluorescent Yellow 0.554 0.445 0.526 0.437 0.569 0.394 0.610 0.390
Fluorescent Orange 0.625 0.375 0.589 0.376 0.636 0.330 0.669 0.331
A
The four pairs of chromaticity coordinates determine the acceptable color in terms of the CIE 1931 Standard Colorimetric System measured with CIE Standard Illuminant
A.
FIG. 1 Three Types of 0/45 (45/0) Instrument
TABLE 14 Climate Types for Use in Outdoor Exposures of
Retroreflective Sheetings
Mean Monthly
Temperature, °F (°C)
A,B
Climate Type Warmest Coldest Representative Example
Month Month of a Typical Location
Tropical summer rain 82 to 93 64 to 72 Miami, FL
(28 to 34) (18 to 22)
Desert 82 to 93 50 to 63 Phoenix, AZ
(28 to 34) (10 to 17)
(optional, but Climate mutually agreed upon between the purchaser
C
recommended) and the seller
A
Climate classification is in accordance with the Koppen reformed classification
system.
B
Outdoor exposure results from Miami, FL and Phoenix, AZ are recognized
internationally as benchmarks for evaluating durability of many different types of
material and products.
C
Outdoor exposures of retroreflective sheeting materials are conducted in loca-
tions representative of several different climates by the National Transportation
Product Evaluation Program (NTPEP) run by AASHTO.
7.6.2 Washing Panels After Exposure—Following exposure, gently wash the panels using a soft cloth or sponge and clean water
or a dilute solution of a mild detergent (1 % by weight in water, maximum concentration). After washing, rinse thoroughly with
clean water, and blot dry with a soft, clean cloth. After washing and drying, condition the panels at room temperature for at least
2 h prior to conducting any property measurements.
7.6.3 Measurement of Coeffıcient of Retroreflection—After panels have been washed, dried, and conditioned in accordance with
7.6.2, measure retroreflectance at 0.2° observation and –4° and 30° entrance angles. Report the average of the coefficient of
retroreflection measured at each geometry on the two panels from each exposure location.
NOTE 4—The use of two samples per weathering deck is considered a minimum and reflects historical practice and practicality. Additional samples
may be weathered, and the results averaged, to decrease the effects of variability associated with the weathering process.
NOTE 5—Weathering tests are generally performed less frequently than other tests in this specification. Judgment must be used to satisfy the user that
weathering results obtained on exposed samples are sufficiently applicable to the material being supplied.
7.7 Colorfastness—Use one of the outdoor weathered outdoor-weathered specimens to test for colorfastness. Wash, dry, and
condition panels in accordance with 7.6.2 and test as specified in 7.4.
D4956 − 19
FIG. 2 Diagram Showing Clamping Bars Used for Attaching Type VI Sheeting Specimens to Test Rack for Outdoor Exposure
7.8 Shrinkage—Condition a 9 by 9-in. (229 by 229-mm) retroreflective sheeting specimen with liner, a minimum of 1 h at
standard test conditions (see 7.1). Remove the liner and place the specimen on a flat surface with the adhesive side up. Ten minutes
after the liner is removed and again after 24 h, measure the specimen to determine the amount of dimensional change.
7.9 Flexibility—Bend the sheeting, in 1 s, around a ⁄8-in. (3.2-mm) mandrel with adhesive contacting the mandrel. For ease of
testing, spread talcum powder on the adhesive to prevent sticking to the mandrel. The test specimen shall be 2 ⁄4 by 11 in. (70 by
229 mm). The test temperature shall be 73 6 3 °F (23 6 2 °C).
7.10 Liner Removal—The protective liner, if any, shall be easily removed following accelerated storage for 4 h at 160 °F (71 °C)
under a weight of 2.5 psi (17.2 kPa).
7.11 Impact Resistance—Apply the retroreflective sheeting to a 3 by 5 by 0.040-in. (76 by 127 by 1.016-mm) 6061-T6
aluminum test panel as specified in 7.2 and test condition as specified in 7.1. Utilizing the test instrument and procedures described
in Test Method D2794, subject the sheeting to the impact of a 2-lb (0.91-kg) weight dropped from the height necessary to generate
an impact of 10 in.-lb (1.13 N-m) when striking a ⁄8-in. (15.8-mm) diameter rounded-tip indenter. The indention formed during
this test shall be an intrusion (in which the panel is struck on the sheeting side and the panel is supported by a steel fixture having
a cylindrical hole as described in Test Method D2794, Section 6.3).
NOTE 6—Test Method D2794 requires the use of a separate weight that falls onto an indenter having a rounded tip. Caution: some impact test equipment
contains a combined weight and indenter having a rounded tip. The use of this combined weight and indenter will result in more severe damage to the
sample as compared to the separate weight and indenter condition. Users are advised that results from the two different test fixtures are not comparable.
7.12 Nighttime Color—Test for nighttime color. Determine the chromaticity in accordance with Test Method E3165 (and further
described in Practice E811 and evaluated using the CIE system in Practice E308.). (The saturation limit shall be considered to
extend to the boundary of the chromaticity locus of spectral colors.) Measure using CIE Illuminant A, observation angle of 0.33°,
entrance angle of +5°, source and receiver apertures not to exceed 10 min of arc, and CIE 1931 (2°) standard observer.
8. General Requirements
8.1 Sheets—When the retroreflective material is in sheet form, the design, dimension, and tolerances shall be as specified by
the purchaser.
8.2 Rolls—When ordered in rolls, the retroreflective material shall be evenly wound on a core of sufficient rigidity to prevent
distortion of the roll. The maximum number of splices shall be 4/50-yd (46-m) roll. Each splice shall be visible at the edge of the
roll. The length and width will be specified by the purchaser.
8.3 Color Processing—The sheeting shall permit color processing with compatible transparent and opaque process colors in
accordance with the sheeting manufacturer’s recommendation at temperatures between 60 to 100 °F (16 to 38 °C) and relative
humidity at 20 to 80 %.
9. Sampling
9.1 To determine conformance to requirements for coefficients of retroreflection for rolls or sheets at least 1 yd (0.914 m) long
of retroreflective sheeting in new (unexposed) condition:
9.1.1 A full width ×by 1 yd (0.914 m) long specimen is selected at random to represent the entire sheet, roll, or lot.
NOTE 7—Samples smaller than 1 yd (0.914 m) long should not be used to judge conformance for full rolls or lots.
D4956 − 19
9.1.2 Three samples are taken from the selected specimen.
FIG. 3 Examples of Proper Spacing for Samples
9.1.2.1 The three samples shall be spaced evenly across (left, center, right) and spaced evenly down the specimen as shown in
the examples in Fig. 3.
9.2 For determining conformance to all other requirements, single samples taken at random shall be tested.
10. Precision and Bias
10.1 The precision and bias for the test methods in Section 7 have not been determined.
11. Packaging and Package Marking
11.1 The sheets or rolls manufactured under this specification shall be packaged in accordance with commercially acceptable
standards. Each package shall be marked with the following:
Name, Brand, or Trademark Lot or Run Number
Quantity Part Number
Size
12. Keywords
12.1 barricades; delineators; highway signing; reboundable sheeting; retroreflective sheeting; traffic control
SUPPLEMENTARY REQUIREMENTS
The following supplementary requirements shall apply only when specified by the purchaser in the
contract or order.
S1. Fungus Resistance
S1.1 Scope—This supplementary specification covers fungus resistance fungus-resistance testing.
S1.2 Test Requirements and Test Methods:
S1.2.1 Test Condition—Unless otherwise specified in this specification, all adhesively bonded and unbonded test samples and
specimens shall be conditioned at a temperature of 73 6 3 °F (23 6 2 °C) and 50 6 5 % relative humidity for 24 h prior to testing.
S1.2.2 Panel Preparations—Unless otherwise specified in this specification, when tests are to be performed using test panels,
the specimens of retroreflective material shall be applied to smooth aluminum cut from Alloy 6061-T6, in accordance with
Specification B209 or B209M, sheets in 0.020-in. (0.508-mm) thickness. The aluminum shall be prepared in accordance with
Specification B449, Class 2 or degreased and lightly acid etched before the specimens are applied. The specimens shall be applied
to the panels in accordance with the recommendations of the retroreflective sheeting manufacturer.
S1.3 Fungus Resistance:
S1.3.1 For use in areas where fungus growth on retroreflective sheeting may be a problem, fungus resistance shall be determined
as specified herein.
S1.3.2 After inoculation with the test organism, Aspergillus niger, and incubation for 14 days, the retroreflective material shall
show no appreciable formation of fungus growth. Any formation of fungus growth shall be noninjurious to the retroreflective
material and shall be removable by wiping with a soft cloth.
D4956 − 19
S1.3.3 Test Organism—The test organism used in this test shall be Aspergillus niger, ATCC Number 6275. Cultures of this
organism shall be carefully maintained on a potato-dextrose agar medium and promptly renewed if there is evidence of
contamination. The stock cultures may be kept for not more than four months in a refrigerator at a temperature between 37 to 50 °F
(3 to 10 °C). Subcultures incubated between 82.4 to 86 °F (28 to 30 °C) for 10 to 14 days shall be used in preparing the inoculum.
S1.3.4 Culture Medium—The culture medium shall have the following composition:
NaNO 3.0 g
K HPO 1.0 g
2 4
MgSO ·7H O 0.5 g
4 2
KCl 0.25 g
Agar 15.0 g
Distilled water to make 1000 mL.
S1.3.5 The pH shall be 5.5 to 6.5; if otherwise, adjust to that range with HCl or NaOH. After mixing, the ingredients
...