ASTM D6901-15(2021)

Standard Specification for Artists' Colored Pencils

ABSTRACT
This standard specification establishes quality requirements for composition, performance, and labeling of artists' colored pencils. This specification also covers vehicles and additives. Labeling requirements shall include company or brand name, identification number, country of origin, colour index names, lightfastness, pencil type, name and address of manufacturer, constitution number, toxicity, and statement of conformance. Additives for colored pencils shall include thickeners, preservatives, surfactants, wax, oil, and humectants. The pencil shall be capable of applying an even coating without scratch marks and without excessive breaking. Lightfastness, color difference test, exposure to natural daylight through window glass, and exposure to Xenon-arc radiation shall be done in accordance with the ASTM standard testing method using white, uncoated, neutral pH, buffered paper or board, without optical brighteners.
SCOPE
1.1 This specification establishes requirements for composition, performance, and labeling of artists’ colored pencils.  
1.2 This specification covers vehicles and additives. Requirements are included for identification, lightfastness, and consistency.  
1.3 Colored pencil specimens are exposed to both natural daylight through window glass and simulated window glass-filtered daylight radiation to determine the lightfastness rating for each pencil.  
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
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: 31-Oct-2021
• ICS: 97.195 - Items of art and handicrafts. Cultural property and heritage
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.57 - Artist Paints and Related Materials

Relations

• Refers: ASTM D4236-94(2016) - Standard Practice for Labeling Art Materials for Chronic Health Hazards
• Effective Date: 01-Dec-2016
• Refers: ASTM D2244-15a - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-Aug-2015
• Refers: ASTM D2244-15 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-Jan-2015
• Refers: ASTM D2244-15e1 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-Jan-2015
• Refers: ASTM D2244-14 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-May-2014
• Refers: ASTM G113-14 - Standard Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
• Effective Date: 01-Mar-2014
• Refers: ASTM E284-13b - Standard Terminology of Appearance
• Effective Date: 01-Nov-2013
• Refers: ASTM E284-13a - Standard Terminology of Appearance
• Effective Date: 01-Jun-2013
• Refers: ASTM E284-13 - Standard Terminology of Appearance
• Effective Date: 01-Jan-2013
• Refers: ASTM E284-12 - Standard Terminology of Appearance
• Effective Date: 01-Jul-2012
• Refers: ASTM D2244-11 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-Jun-2011
• Refers: ASTM D4236-94(2010) - Standard Practice for Labeling Art Materials for Chronic Health Hazards
• Effective Date: 01-Dec-2010
• Refers: ASTM D4303-10 - Standard Test Methods for Lightfastness of Colorants Used in Artists' Materials
• Effective Date: 01-Jun-2010
• Refers: ASTM G151-10 - Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
• Effective Date: 01-Apr-2010
• Refers: ASTM D2244-09a - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-Aug-2009

Overview

ASTM D6901-15(2021): Standard Specification for Artists' Colored Pencils is an internationally recognized standard developed by ASTM International. This specification establishes essential requirements for the composition, performance, and labeling of artists' colored pencils. The standard ensures that colored pencils meet consistent quality benchmarks, including requirements for vehicles, additives, identification, lightfastness, and uniformity. It also sets rigorous test methods for assessing a pencil’s colorfastness and includes detailed labeling protocols to meet both manufacturers' and artists’ needs.

Key Topics

• Composition and Additives: Specifies acceptable materials for colored pencils, such as pigments, extenders, binders, and additives. Essential additives can include thickeners, preservatives, surfactants, wax, oil, and humectants to achieve required consistency and stability.
• Performance Criteria: Colored pencils must apply an even coating of color without excessive breaking, scratching, or crumbling under standard use conditions.
• Lightfastness and Testing: Encompasses standardized procedures for determining resistance to light-induced color change. Specimens are exposed to both natural daylight through window glass and simulated daylight using xenon-arc radiation. Only pencils conforming to Lightfastness Categories I and II meet the ASTM D6901 standard.
• Labeling Requirements: Mandates comprehensive labeling on pencils and packaging. Necessary details include company or brand name, identification number or color name, country of origin, color index names and constitution numbers, lightfastness rating, pencil type, manufacturer’s contact information, toxicity information, and a clear statement of conformance.
• Quality Assurance: Addresses acceptable variances in manufacturing and testing, ensuring repeatable and reproducible results within specified tolerances across different test conditions.

Applications

ASTM D6901 is vital for:

• Artists and Art Educators: Assures users that colored pencils meet strict requirements for performance, color consistency, and long-term durability, aiding in the selection of high-quality materials.
• Manufacturers: Provides a standardized framework for producing and marketing artists’ colored pencils, facilitating reliable quality claims and product differentiation in international markets.
• Retailers and Distributors: Ensures that products comply with industry norms, informing purchasing decisions and supporting product credibility with end users.
• Testing Laboratories: Outlines precise procedures for specimen preparation, exposure, and color measurement, promoting reliable assessment of colored pencil lightfastness and general quality.
• Regulatory and Trade Compliance: Meets internationally recognized standardization principles, aiding compliance with global regulations, such as those required under the World Trade Organization Technical Barriers to Trade (TBT) Agreement.

Related Standards

ASTM D6901 references and aligns with several other ASTM standards, including:

• ASTM D2244: Calculation of Color Tolerances and Color Differences
• ASTM D4236: Labeling Art Materials for Chronic Health Hazards
• ASTM D4303: Lightfastness Testing for Colorants Used in Artists’ Materials
• ASTM G24, G151, G155: Exposure of Nonmetallic Materials to Natural or Accelerated Weathering
• ASTM E284: Terminology of Appearance

These referenced documents collectively support the robust methodology used in ASTM D6901 for evaluating, labeling, and marketing high-quality artists’ colored pencils.

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Adhering to ASTM D6901-15(2021) enhances the reliability, safety, and consistency of artists’ colored pencils, benefiting manufacturers, artists, and consumers worldwide. This standard is a key reference for anyone involved in the production, testing, or purchase of professional colored pencils. For more information and access to the standard, consult the ASTM International website.

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: D6901 −15 (Reapproved 2021)
Standard Specification for
Artists’ Colored Pencils
This standard is issued under the fixed designation D6901; 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.
1. Scope G113 Terminology Relating to Natural andArtificial Weath-
ering Tests of Nonmetallic Materials
1.1 This specification establishes requirements for
G151 Practice for Exposing Nonmetallic Materials inAccel-
composition, performance, and labeling of artists’ colored
erated Test Devices that Use Laboratory Light Sources
pencils.
G155 Practice for Operating XenonArc LampApparatus for
1.2 This specification covers vehicles and additives. Re-
Exposure of Materials
quirements are included for identification, lightfastness, and
consistency.
3. Terminology
1.3 Colored pencil specimens are exposed to both natural
3.1 Definitions—Refer to Terminology E284 for appearance
daylight through window glass and simulated window glass-
terms used in this specification and to Terminology G113 for
filtered daylight radiation to determine the lightfastness rating
terms relating to natural and artificial lightfastness tests.
for each pencil.
3.2 Definitions of Terms Specific to This Standard:
1.4 The values stated in SI units are to be regarded as the
3.2.1 bloom, n—a cloudy exudation on the surface of
standard. The values given in parentheses are for information
colored pencil due to wax migration.
only.
3.2.2 burnish, v—to firmly rub the surface of the sample
1.5 This international standard was developed in accor-
following application of the colored pencil until the binder
dance with internationally recognized principles on standard-
breaks down and the color is forced into the texture of the
ization established in the Decision on Principles for the
substrate to improve coverage.
Development of International Standards, Guides and Recom-
3.2.3 colored pencil, n—a core of extenders, binders, pig-
mendations issued by the World Trade Organization Technical
mentsandadditives,suchaswax/oilandthickenerssurrounded
Barriers to Trade (TBT) Committee.
by a casing.
2. Referenced Documents
3.2.4 color stick, n—a core of extenders, binders, pigments
and additives, such as wax/oil and thickeners without a casing
2.1 ASTM Standards:
but sometimes with a paper sleeve.
D2244 Practice for Calculation of Color Tolerances and
Color Differences from Instrumentally Measured Color
3.2.5 substrate, n—white, uncoated, neutral pH, buffered
Coordinates
paper, or board, without optical brighteners, to which color is
D4236 Practice for Labeling Art Materials for Chronic
applied.
Health Hazards
3.2.6 watercolor pencil, n—a colored pencil with a water-
D4303 Test Methods for Lightfastness of Colorants Used in
dispersible core.
Artists’ Materials
3.2.7 water-soluble color stick, n—a water-dispersible color
E284 Terminology of Appearance
stick.
G24 Practice for Conducting Exposures to Daylight Filtered
Through Glass
4. Significance and Use
4.1 This specification establishes quality requirements and
This specification is under the jurisdiction of ASTM Committee D01 on Paint
provides a basis for common understanding among producers,
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.57 on Artist Paints and Related Materials.
distributors, and users.
Current edition approved Nov. 1, 2021. Published November 2021. Originally
4.2 It is not intended that all pencils meeting the require-
approved in 2003. Last previous edition approved in 2015 as D6901 – 15. DOI:
10.1520/D6901-15R21.
ments be identical nor of uniform excellence in all respects.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Variations in manufacture, not covered by this specification,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
may cause some artists to prefer one brand over another, either
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. of which may be acceptable under this specification.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6901 − 15 (2021)
4.3 Variation in test results can result from differences in 5.3 Toxicity—All products and labeling must conform to the
pigment manufacture from time to time in a company, different Federal Hazardous Substances Act and to ASTM Practice
varieties of a pigment from company to company, different D4236.
combinations of pigments and other ingredients, specimen
5.4 Statement of Conformance—Provide Statement of Con-
preparation, different instruments and instrumental readings,
formance in literature and on packaging container if all pencils
variations in the surface of the specimen, and the conditions of
in the container are Lightfastness I or II: “Conforms toASTM
exposure.Allowance for these variations is made by establish-
Specification D6901,” or “Conforms to ASTM D6901.” This
ing lightfastness categories, each of which covers a defined
statement may be combined with other conformance
range of color loss.
statements, such as, “Conforms to the quality and health
4.4 Since a specific colored pencil may be unusually sensi- requirements of ASTM Specification D6901 and Practice
D4236.”
tive to some aspect of a particular method of accelerated
lightfastness testing and show a change in color that would not
6. Quality Assurance for Artists’ Colored Pencils
occur in a normal home or gallery environment, two types of
exposure are required.
6.1 Conditions Not Covered in This Specification that Affect
Colored Pencils:
4.5 Some variation in test results is to be expected even
6.1.1 Substrate—The effective pH of the paper used will
when the same type of exposure is repeated; therefore, after
affect the long-term color appearance of the applied color.
triplicate specimens are exposed in each type of exposure, any
outlierisdiscardedandthemeanofthespecimensiscalculated 6.2 Additives—Thickeners, preservatives, surfactants, wax,
oil, and humectants may be used to achieve consistency,
for each exposure type to determine the lightfastness category
for each. If the two types of exposures place colored pencil in prevent microbial deterioration, and control application results.
the same lightfastness category, it is the category for that
6.3 Pencils shall be capable of being applied in a smooth,
pencil. Instead of testing a third time if the two types of
uniform coating of color without scratch marks.
exposures place the colored pencil in different lightfastness
6.4 The colored lead shall not crumble or break excessively
categories, producers may elect to use the poorer of the two
when used with pressure sufficient to apply the color smoothly.
relevant lightfastness categories.
4.6 Variations in specimen preparation and measurement 7. Specimen Preparation and Exposure
may result in as much as 4 units of CIE 1976 L*a*b*
7.1 Materials:
(CIELAB) color difference∆E*, calculated using the equation
7.1.1 Colored Pencils, Watercolor Pencils, Color Sticks or
given in Practice D2244, between the measurements of a test
Water-soluble Color Sticks—Materials to be tested.
specimen before and after exposure; therefore, only color
7.1.2 Substrate—White paper or board. To avoid substrate
differences greater than 4 ∆E* are considered color loss.
discoloration during the testing procedures, the substrate shall
be 100 % cotton, acid free, buffered, uncoated, and contain no
5. Labeling Requirements
optical brighteners.
5.1 Provide on the Pencil:
7.2 Preparation of Test Specimens:
5.1.1 Company or brand name.
7.2.1 Prepare ten specimens of each pencil or stick to be
5.1.2 Company assigned identification number for the
tested. Cut the paper substrate into a size that fits the holder to
pencil, or company assigned color name for the pencil, or both;
be used for exposure. Draw a specimen square 28 by 28 mm
1 1
however, pigment names shall not be used as pencil names
(1 ⁄8 by 1 ⁄8 in.) in the center of each paper substrate. Leave
unlessthepencilcontainsonlythatpigment,oravariantofthat
enough white substrate around each specimen so that the
pigment, or that pigment and white; otherwise the word “Hue” colored portion will not be damaged by handling or instrument
must be added to the name.
mounting hardware. Using constant pressure, color each speci-
5.1.3 Country of origin. men substrate evenly and firmly with the colored pencils,
watercolor pencils, color sticks, or water-soluble color sticks.
5.1.4 The Colour Index Names of the pigments used in the
Repeat as necessary to completely cover the square drawn on
pencil if space permits.
the substrate. In the case of a metallic color, finish with parallel
5.1.5 Lightfastness—Lightfastness Category indicated by
strokes in whichever direction results in an even metallic
the symbols I, II, III, IV or V. Only colored pencils in
sheen. Burnish each sample to make coverage as complete and
Lightfastness Categories I and II conform with this Specifica-
uniform as possible.
tion.
NOTE 1—It is difficult to achieve an even coating of the color with
5.2 Provide in Literature Included in Packaging Container
complete hiding of the substrate. If the substrate is not completely
and at Points of Purchase:
covered, measurement will vary from spot to spot. If the coating has
5.2.1 Identification of the type of pencil: colored,
varying thicknesses, the specimen will fade unevenly. In these cases the
watercolor, color stick, water-soluble color stick.
complete surface of the substrate in the colored area may have to be
measured to get a repeatable and reproducible measurement that repre-
5.2.2 Name and address of manufacturer, importer or sup-
sents the average color of the specimen. If a 25 mm (1 in.) diameter
plier.
instrument measuring port is used, the whole colored surface of the
5.2.3 The Colour Index name and Constitution Number of
specimen is measured; if a smaller measuring port is used, additional
every pigment in each pencil. measurements of different portions of the colored surface of the specimen
D6901 − 15 (2021)
are necessary to accurately represent the color.
7.4.4.1 Use a xenon-arc device that conforms to the require-
ments defined in Practices G151 and G155. Unless otherwise
7.3 Color Measurement Prior to Exposure:
specified, the spectral power distribution of the xenon-arc
7.3.1 Prior to conducting the measurements described in
deviceshallconformtotherequirementsinPracticesG151and
7.3.2, gently wipe each specimen with cotton to remove any
G155 for xenon arc radiation through a window glass filter.
surface bloom. Repeat this step immediately before specimen
7.4.4.2 Place specimens in the test device in positions that
exposure.
conform with irradiance uniformity specified in Practice G151,
7.3.2 The color difference among the ten replicate speci-
or to assure equal radiant exposure, reposition specimens
mens and the uniformity of color on each specimen shall be <4
during exposure.
CIELAB units. Color measurements are made using either a
NOTE 2—Replicate specimens should not be placed near one another
spectrophotometer, spectrocolorimeter, or colorimeter set to
during the exposures.
use Illuminant D65 and the 1964 10° observer and excluding
specular reflection from the measurement. Reproducibility
7.4.4.3 Whenonlyafewcoloredpencilspecimensarebeing
among specimens can be determined using a 25 mm, viewing
exposed in a small xenon-arc device, test all triplicates at the
port on the color measurement device. For color uniformity same time. However, if there are too many specimens for all
across the colored area, use a 10 mm or smaller viewing port.
triplicates to fit in the device at once, test one or two replicate
If the color difference among specimens or non-uniformity specimens at a different time.
across the specimen exceeds 4 CIELAB units, apply more
NOTE 3—To track the rate of color change in specimens as a function
color to specimens as needed until they meet the uniformity
of radiant exposure in the xenon-arc device, the radiant exposure of 1260
requirement.
MJ/m can be divided into three or more phases and the device
programmed to stop at he end of each phase so the color can be measured
7.3.2.1 When using a 25 mm viewing port, make three
and recorded. The specimens are then returned to the test chamber and
measurements. After each measurement, lift, partially rotate
exposure is continued until the specified radiant exposure is reached.
the specimen, and reposition the viewing port for the next
7.4.4.4 Unless agreed otherwise, in a xenon-arc device that
measurement. Find the mean of these measurements in
controls at 340 nm, the irradiance at the control point shall be
CIELAB units and record it as the value for the unexposed
0.35 6 0.02 W/(m ·nm) at 340 nm and specimens exposed to
specimen.
100 % light to reach a total radiant exposure of 510 kJ/(m ·nm)
7.3.2.2 When using an instrument with a 10 mm or smaller
at 340 nm, the calculated equivalent of 1260 MJ/m of full
measuring port, make 5 measurements. After each
spectrum solar radiation. For a xenon-arc device that controls
measurement, lift, partially rotate the specimen, and reposition
exposure at 300 to 800 nm, the irradiance at the control point
the measuring port for the next measurement. Find the mean of
shall be 500 6 75 /w/m at 300 to 800 nm and specimens
thesemeasurementsinCIELABunitsandrecorditasthevalue
exposed to 100 % light to reach a total radiant exposure of 739
for the unexposed specimen.
MJ/m at 300 to 800 nm. For xenon-arc devices that control
7.4 Exposure:
exposures in a different spectral region, consult the manufac-
7.4.1 Three specimens of each color shall be exposed to
turer of the device for the irradiance and radiant exposure
glass filtered solar radiation using MethodA. In addition, three
required to produce equivalent test results. For further infor-
specimens shall be exposed in a xenon-arc device operating
mation see Appendix XI in Test Methods D4303.
with window glass filters using Method B or C. One specimen
7.4.4.5 The uninsulated black panel temperature shall be 63
of each color shall be retained for visual comparison with test
6 2 °C. For the equivalent insulated black panel temperature,
specimens following exposure, and three specimens shall be
consult the manufacturer of the device.
retained for use in a third exposure, if needed.
NOTE 4—Each of the set points and its tolerances specified represent an
7.4.2 Store the retained, unexposed specimens in the dark
operational control point for equilibrium conditions at a single location in
unless the formulation includes oil. Store specimens that
the cabinet, which may not necessarily represent the uniformity of these
contain oil in subdued light, 500 to 750 lx (50 to 75 fc), to conditions throughout the cabinet. The set point is the target condition for
the control sensor with the exact number specified programmed by the
prevent yellowing. If specimens must be stored for as long as
user. The operational fluctuation given with the set point does not imply
100 days, store then in the dark, but remove those containing
that the user is allowed to program a set point higher or lower than the
oil and place in subdued light for at least seven days b
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