Significance and Use

Although color measuring instruments are widely used, color matches are usually checked visually. The standardization of visual examination has greatly improved the uniformity of products and the accuracy of color matches.

The use of this practice is essential for critical color matching but is also recommended for any color appraisal, such as the choice or approval of a color. This practice is widely used in industry to choose colors, exhibit colors reproducibly, inspect incoming materials, monitor color producing processes, and inspect finished goods. Visual appraisal is particularly important when the product inspected is not of the same material as the color standard to which it is compared.

Observers This practice is based on the fundamental assumption that the observer has normal color vision and is trained and experienced in observing and classifying color differences. The significance of the results depends on that being so. The selection, evaluation, and training of observers are treated in Guide E1499 .

Illumination Simulated average daylight is recommended by the International Commission on Illumination (CIE), but a slightly bluer simulated north-sky daylight came into widespread use in North America, because it provides a slightly greater distinction between very pale yellow and white, a distinction of great commercial importance.

1. Scope

1.1 This practice specifies the equipment and procedures for visual appraisal of the colors and color differences of opaque materials that are diffusely illuminated. These specification are of critical importance in color matching. This practice requires judgments by observers with normal color vision.

1.2 Critical visual appraisal of colors and color differences of materials such as metallic and pearlescent paints requires illumination that is nearly a geometric simulation of sunlight, because such directional illumination permits observation of the glitter and goniochromatism that characterize such materials. Such viewing conditions are beyond the scope of this practice.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.4 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.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D523 Test Method for Specular Gloss

D1535 Practice for Specifying Color by the Munsell System

D4086 Practice for Visual Evaluation of Metamerism

D5531 Guide for Preparation, Maintenance, and Distribution of Physical Product Standards for Color and Geometric Appearance of Coatings

E284 Terminology of Appearance

E308 Practice for Computing the Colors of Objects by Using the CIE System

E1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation

E1499 Guide for Selection, Evaluation, and Training of Observers

ISO/CIE Standard

Keywords

color; color difference; color matching; lighting; viewing conditions; visual examination color; visual examination color difference; Visual examination--paints/related coatings/materials; Color--paints/related coatings/materials; Color difference measurements; Diffuse light transmission; Geometric analysis--paints/related coatings/materials; Latex paints; Light transmission and reflection; Opacity/opaque materials; Radiometers; Spectral data--paints/related coatings; Spectroradiometric data analysis;

ICS Code

ICS Number Code 17.180.20 (Colours and measurement of light)

DOI: 10.1520/D1729-96R09

ASTM International is a member of CrossRef.

ASTM D1729