Spectrophotometric and colorimetric determination of the colors of the TCCA standard color cards

Abstract

The color c ards of the Textile Color Card Association of the United Stat es are widely used i n the textile and a lli ed industries and by many p rocuring agencies o f t h e Federal Government. The Textile Color Card Association issues both seasonal and standard color cards. The seasonal car ds p rovide a color-fo recastin g sery ice to textile manufacturers and promote color coord ination am ong t h e t rades; the standard cards present colors for which there is a popu la r and continuing demand. Most impor tant of the color cards is t he Standar d Color Card of Ameri ca, the current nint h ed ition containi ng 216 colors. Preeminent amon g t he m a ny special sets of color cards iss ued by t he Association for use of the Federa l Governm ent is t h e United States Army Color Card showing 22 official colors for the arms and services. T he specification of the colors of t he Ninth Edition Standard Color Card and the Un ited States Army Color Card h as been undertaken for the pur pose of correlating these textile standar ds with American War Standard Z44-1942 for the specification and description of color. T he 238 samples comprising these color cards have been examined by basic spectrophotometric and colorimetric procedures. From th is study t here have been foun d d ayli ght r eflectance, Y, ch romaticity coordinates (x,y) , Munsell renota.t ions, and I SCC-NBS color designations for these samples, as recommended by American W ar Stan dar d Z44-1942. As more than half of these texti le s tandards a re flu orescent, and as existing spect.rophotometers are not sui ted t o t h e evaluation of such samples, considerahle reliance has been p laced on q uantitative co lorimetri c an d p hotometric comparisons with t h e Munsell colo r standards, both by means of a chromati city-difference colorimet.er and by t he Martens p h otom eter.As a closing check, Munsell book notations of these textile standards h ave been obtained by a direct visual comparison with the color scales of t he Munsell Book of Color.

Comparison of real colour gamuts using a new reflectance database

“…The first real colour gamut was derived in 1951 by Wintringham and published in a tutorial paper on colour television and colorimetry. The gamut was derived from four sets of data: the Munsell Book of Color, the Ostwald Color Atlas, the Textile Color Card Association and a set of printing inks. Since Wintringham was not concerned with the lightness dimension, the gamut derived was an overall projection gamut on to CIE x , y chromaticity diagram.…”

Circular of the Bureau of Standards no. 478:

“…If the surfaces be not spectrally similar, or if they be viewed through many yellow and green filters, a faint projection of the macular pigment may appear in the photometric field. Such an appearance lowers the precision of setting somewhat and is also correlated with failure of the result to agree with indirect colorimetry by way of the spectrophotometer [118]. This failure may often be by as much as 0.003 in x or y.…”

“…This colorimeter has been used in setting up a color standard for ruby mica [63], for inspection of working standards, transparent and opaque, for conformity to a master standard ( such as the Kitchen and Bathroom Accessory Colors), and for general colorimetry by difference both for fluorescent and nonfluorescent specimens [118].…”

“…All colors of these standard and seasonal cards are identified by name and cable number. The standard colors have been measured at the National Bureau of Standards by spectrophotometric and colorimetric procedures ; and luminous reflectance, F, relative to magnesium oxide, and chromaticity coordinates, x,y, for illuminant C have been published [118].…”