ASTM D3134-97(2003)

Standard Practice for Establishing Color and Gloss Tolerances

SIGNIFICANCE AND USE
Color specifications are centered around exact positions in color space. Correspondingly, gloss specifications are centered around an exact position on the gloss scale. Because it is difficult to achieve these exact positions repeatedly, it is necessary to specify tolerances that are acceptable to both the buyer and the seller. This practice details the procedure for accomplishing this goal.
SCOPE
1.1 This practice describes a procedure for establishing tolerances and evaluating the color and gloss of specimens with respect to specified standards. This practice is appropriate for nonfluorescent opaque specimens.
1.2 This practice does not indicate the extent of tolerances, but gives guidance on how they can be set. For product specification, the tolerances between specimens and the specified standard should be agreed upon between the purchaser and the seller.
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Nov-2003
• ICS: 87.040 - Paints and varnishes
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.11 - Visual Methods

Relations

• Replaces: ASTM D3134-97 - Standard Practice for Establishing Color and Gloss Tolerances
• Effective Date: 01-Dec-2003
• Replaced By: ASTM D3134-97(2008)e1 - Standard Practice for Establishing Color and Gloss Tolerances
• Effective Date: 01-Dec-2008
• Referred By: ASTM D5531-17(2023) - Standard Guide for Preparation, Maintenance, and Distribution of Physical Product Standards for Color and Geometric Appearance of Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM D3794-22 - Standard Guide for Testing Coil Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM D5382-02(2017) - Standard Guide to Evaluation of Optical Properties of Powder Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM D6577-15(2019) - Standard Guide for Testing Industrial Protective Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM E1808-96(2021) - Standard Guide for Designing and Conducting Visual Experiments
• Effective Date: 01-Dec-2003
• Referred By: ASTM C647-19 - Standard Guide to Properties and Tests of Mastics and Coating Finishes for Thermal Insulation
• Effective Date: 01-Dec-2003
• Referred By: ASTM D1535-14(2023) - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Dec-2003
• Referred By: ASTM D7195-21 - Standard Guide for Setting Object Color Specifications
• Effective Date: 01-Dec-2003
• Referred By: ASTM D3451-06(2017) - Standard Guide for Testing Coating Powders and Powder Coatings
• Effective Date: 01-Dec-2003
• Referred By: ASTM E1499-16(2023) - Standard Guide for Selection, Evaluation, and Training of Observers
• Effective Date: 01-Dec-2003
• Referred By: ASTM E1345-98(2019) - Standard Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements
• Effective Date: 01-Dec-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D3134–97(Reapproved2003)
Standard Practice for
Establishing Color and Gloss Tolerances
This standard is issued under the fixed designation D 3134; 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.
INTRODUCTION
Permissible color and gloss deviations from a standard are generally dependent upon the color
discrimination of the observer, on the lighting and surround in which the material is viewed, and on
special considerations related to the design, manufacture, and practical usage of the colored material
or object. The tolerances, therefore, may be influenced by economic, technical, psychological, and
practical requirements. In many circumstances, acceptability of color and gloss deviations from a
standard may differ appreciably from the perceptibility of deviations such as on-tone fading
preferences, large tolerances for luminance variation, nongreen bias, or nonyellow bias. With proper
allowances, perceptibility data can be used as an aid to develop permissible tolerances. Finally, the
sum of all these considerations should result in a specification acceptable to both buyer and seller.
1. Scope D 2244 Practice for Calculation of Color Tolerances and
Color Differences from Instrumentally Measured Color
1.1 This practice describes a procedure for establishing
Coordinates
tolerancesandevaluatingthecolorandglossofspecimenswith
D 3964 Practice for Selection of Coating Specimens for
respect to specified standards. This practice is appropriate for
Appearance Measurement
nonfluorescent opaque specimens.
D 4449 Test Method for Visual Evaluation of Gloss Differ-
1.2 This practice does not indicate the extent of tolerances,
ences Between Surfaces of Similar Appearance
but gives guidance on how they can be set. For product
D 5531 Guide for Preparation, Maintenance, and Distribu-
specification, the tolerances between specimens and the speci-
tion of Physical Product Standards for Color and Geomet-
fiedstandardshouldbeagreeduponbetweenthepurchaserand
ric Appearance of Coatings
the seller.
E 284 Terminology of Appearance
1.3 This standard does not purport to address all of the
E 308 Practice for Computing the Colors of Objects by
safety concerns, if any, associated with its use. It is the
Using the CIE System
responsibility of the user of this standard to establish appro-
E 312 Practice for Description and Selection of Conditions
priate safety and health practices and determine the applica-
for Photographing Specimens
bility of regulatory limitations prior to use.
E 805 PracticeforIdentificationofInstrumentalMethodsof
2. Referenced Documents Color or Color-Difference Measurement of Materials
E 1164 Practice for Obtaining Spectrophotometric Data for
2.1 ASTM Standards:
Object-Color Evaluation
D 523 Test Method for Specular Gloss
E 1331 Test Method for Reflectance Factor and Color by
D 1535 Practice for Specifying Color by the Munsell Sys-
Spectrophotometry Using Hemispherical Geometry
tem
E 1345 Practice for Reducing the Effect of Variability of
D 1729 Practice for Visual Appraisal of Colors and Color
Color Measurement by Use of Multiple Measurements
Differences of Diffusely Illuminated Opaque Materials
E 1349 Test Method for Reflectance Factor and Color by
Spectrophotometry Using Bidirectional Geometry
E 1360 Practice for Specifying Color by Using the Optical
This practice is under the jurisdiction of ASTM Committee E12 on Color and
Society of America Uniform Color Scales System
Appearance and is the direct responsibility of Subcommittee E12.11 on Visual
E 1499 Guide to the Selection, Evaluation, and Training of
Methods.
Observers
Current edition approved Dec. 1, 2003. Published December 2003. Originally
approved in 1972. Last previous edition approved in 1997 as D 3134 – 97.
E 1541 Practice for Specifying and Matching Color Using
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the Colorcurve System
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
E 1708 Practice for Electronic Interchange of Color and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Appearance Data
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3134–97 (2003)
2.2 CIE Publication: the standard is textured. (If the standard is textured, note the
No. 15.2 Colorimetry 2nd ed. texture orientation during measurement.) The variability of the
measurements due to texture may be reduced by following the
3. Terminology
recommendations outlined in Practice E 1345.
3.1 Definitions—For definitions of terms related to this
7.1.1.2 Visual Color Assessment—Use Guide E 1499 to
practice see Terminology E 284.
select an observer for the assessment. Assess and specify the
color in terms of a color system described in Practices D 1535,
4. Summary of Practice
E 1360, or E 1541.
4.1 This practice consists of recommendations for the se-
7.1.1.3 Measure the gloss in accordance with Test Method
lection of a standard, the necessary physical measurements to
D 523, or evaluate it in accordance with Test Method D 4449.
assess the permanence of the standard to reproduce it when
7.1.1.4 Employ photography for permanently recording the
needed, and to establish tolerances.
appearance of the surface texture (see Practice E 312). While
4.2 Recommendationsaregivenforthedeterminationofthe
Practice D 3134 does not deal with texture tolerances or
conformance of a specimen to preestablished color and gloss
specifications, it should be recognized that significant differ-
tolerances by instrumental or visual means.
ences in surface texture between standard and test specimens
significantly affect both color and gloss, whether examined
5. Significance and Use
visually or instrumentally. In the case of visual evaluation of
5.1 Color specifications are centered around exact positions
the effect of color and gloss, differences can be minimized by
in color space. Correspondingly, gloss specifications are cen-
strict adherence to recommended illuminating and viewing
tered around an exact position on the gloss scale. Because it is
geometry (see Practice D 1729).
difficult to achieve these exact positions repeatedly, it is
7.2 Selection and Specification of Color Tolerances:
necessary to specify tolerances that are acceptable to both the
7.2.1 The purchaser and the seller shall agree on color
buyer and the seller. This practice details the procedure for
toleranceswithrespecttoapreviouslyselectedstandardandon
accomplishing this goal.
the color scales in which they are expressed. Selection of the
6. Specimens magnitude and direction of color tolerances shall be based on
careful consideration of all applicable factors. For example,
6.1 The exact method of preparation of the specimen shall
tolerances may be selected on the basis of perceptibility of the
be agreed upon between the purchaser and the seller. However,
magnitude of color difference, rejection of or closer limits on
for the highest precision in instrumental measurements the
certain directions of color difference, and costs of controlling
specimens should be opaque, uniform in color, plane, and
the magnitude and direction of color difference. Recommen-
uniform in texture. The specimens should be relatively perma-
dations on color scales appear in CIE Publication No. 15.2 and
nent, and capable of being cleaned. Preferred sizes of speci-
Practice E 308.
mens for visual evaluation are given in Practice D 1729, the
specific size being governed by the use of the specimens. 7.2.1.1 Express color differences between the specimen and
the standard in terms of a set of three independent parameters.
7. Procedure
TheCIE1976L*a*b*(CIELAB)approximatelyuniformcolor
space and color difference equations have been recommended
7.1 Selection and Specification of Color and Gloss Stan-
dard: forusebytheInternationalCommissiononIllumination(CIE).
See Practice D 2244 and Practice E 308. While this color
7.1.1 Select a standard in accordance with Practice D 3964
that is preferably the same type of material as the specimens to metric (CIELAB) is convenient for expressing color differ-
be evaluated for color or gloss, or both. Prepare, in sufficient ences, it must be understood that a given calculated color
quantity, secondary standards in accordance with Guide difference in one region of color space may not represent the
D 5531thatarerepresentativeofthedesiredcolorandgloss,in same visual difference in other regions of color space.
the permanent material. Standards should have the same
7.2.2 Glossdifferencescanaffectinstrumentalmeasurement
spectral characteristics as the manufactured product. This is
of color differences. Large gloss differences between visually
usuallyaccomplishedbyuseofthesamecolorantcomposition,
identical colors can cause their color measurements to exhibit
incorporated in the same manner into the same material. The
largercolordifferencesthaninfactexist.Whenusinghistorical
standard should have the same texture as the manufactured
data to establish color tolerances, exercise care to limit the
product.
specimens to those that have quite similar gloss values. When
7.1.1.1 In order to obtain a permanent record, use Practice
establishing gloss tolerances, be aware that changes in gloss
E 805andeitherTestMethodE 1331orTestMethodE 1349to
values may have an effect upon color measurements.
correctly identify the instrumental measurement method. Mea-
7.2.3 Whencolordifferenceformulaeareusedinpractice,it
sure the color in accordance with Practices E 1164 and E 805.
is often desirable to identify the components of color differ-
Report the color as described in Practice E 308. Do this even if
ence, in terms of correlates of lightness, hue, and perceived
chroma (saturation). It is also desirable to express color
specificationsintermsofsuchcorrelates.TheCIEterminology
Available from The U.S. National Committee of the CIE (International
appropriate to this usage is CIE 1976 lightness, CIE 1976
Commission on Illumination), C/oThomas M. Lemons,TLA-Lighting Consultants,
Inc., 7 Pond St., Salem, MA 01970. hue-angle, h , and CIE 1976 chroma, C* . Refer to Practice
ab ab
D3134–97 (2003)
D 2244 and Practice E 308 for equations and definitions. The 7.2.5.4 The scales on Fig. 2(a) and Fig. 3(b) are changed
CIELAB 1976 hue-angle and chroma are illustrated in Fig. 1. from absolute values (L*, a*, b*) into color difference values
(DL*, Da*, Db*) as shown .
7.2.4 TheCIELABopponent-colorred-greencoordinate a*,
and the yellow-blue coordinate b* are defined in Practice
7.2.6 When tolerances for each color attribute (hue, light-
D 2244 and Practice E 308. ness,andsaturationorchroma)aresymmetricalintheplusand
7.2.5 Graphical Interpretation of Historical Data: minus directions, the graphical representation is a regular
geometric figure that can be represented mathematically, as by
7.2.5.1 Color tolerances can be determined from a graphical
interpretation of historical data (batches accepted, rejected, or the equation for an ellipse or an ellipsoid. It is also common to
represent color tolerances by a set of six points: light and dark
considered borderline). Fig. 2 (a) and Fig. 3(b) show plots of
specimensratedbymultipleobserverswithrespecttohowwell limits, low and high saturation limits, and two adjacent hue
limits. Such representation may involve some sacrifice in
they match a standard, along with figures defining the toler-
ances. To illustrate the principle recommended: (1) rate a accuracy of the tolerance specification and should be used with
care.
number of specimens for acceptability, (2) plot them, and (3)
prepare to draw the tolerance figure dictated by the data.
7.2.7 In general, color tolerances will not be symmetrically
7.2.5.2 In such cases it is customary to plot the hue angle of located in all directions about the standard color in any color
the standard by drawing a line from the origin (0, 0) through space. (see Fig. 2(a) and Fig. 3(b)). However, in some
the standard color on the a*b* plot. This line of constant hue instances the asymmetry may be small enough that the color
tolerances may be represented by a single, overall color
becomes the major axis. Similarly, a line perpendicular to the
constant-hue line and passing through the standard color is a difference (DE) that represents the radius of a sphere about the
standard in color space.
line of constant chroma (or saturation) and becomes the minor
axis of the ellipse, if the data plot indicates the ellipse should
7.2.8 Finally, there are many deviations from the regular
be symmetrical around the standard color. These lines assist in geometric figures described in 7.2.6 and depicted in Fig. 2(a)
drawing the tolerance ellipse, Fig. 2(a).
and Fig. 3(b). The nongreen and nonyellow biases mentioned
7.2.5.3 To determine lightness tolerances it is necessary to in the introduction are but two of these. For example, the
plot the data for the same colors on a graph showing L* along tolerance figure may not be regular; perhaps it will be an ovoid
with either a* and b*, and draw a tolerance ellipse as in Fig. instead of an ellipse; its major axis may deviate from the
3(b). The choice between a* and b* is dictated by which of direction of constant hue; and the standard color may be far
these attributes cover the greater range. from its center. Frequently when it is necessary to set color
tolerances, the amount of historical accept-reject data will be
toomodestforthispurpose.Itisthereforenecessarytomonitor
tolerances, once set, to ensure that they appropriately address
the color quality control requirement.
7.2.9 Whentolerancestandardsarepreparedtoillustratethe
color in the hue, lightness, and saturation or chroma attributes
of color space and to allow visual interpretation of the
conformity of color, inspection should be under specified light
sources following the recommendations in Practice D 1729.
Gonioapparent coatings or materials require special method-
ologies for viewing and measurement.
7.3 Selection and Specification of Gloss Tolerances:
7.3.1 The gloss tolerances around the gloss of the standard
may be expressed in gloss units (SeeTest Method D 523)oras
a percent.
7.3.2 Withfewexceptions,thevisualglosstolerancewillbe
symmetrical around the nominal value of the standard. It will
be necessary to determine experimentally the instrumental
readings that correspond to the required visual differences.
7.3.3 When the gloss desired is at or near the maximu
...