Aatcc Gray Scale For Staining & Color Change

Gray Scale for Staining
This scale is used in colorfastness tests for evaluating staining on undyed textiles. The scale consists of pairs of nominally white and gray color chips each representing a difference in color or contrast (shade and strength) corresponding to a numerical grade for staining. The fastness grades of the scale steps and the corresponding color difference and tolerances are determined by the CIE L*a*b* (CIELAB) formula. Fastness grade 5 is represented on the scale by two identical white reference chips mounted side by side, having reflectance of not less than 85 percent. Fastness grades 4.5 to 1, inclusive, are represented by a reference white chip identical with those used for grade 5 paired with similar but neutral gray chips

Gray Scale for Color Change
This scale is used in visual evaluation of the changes in color of textiles resulting from colorfastness tests. The colorfastness grades of the scale steps and the corresponding total color differences and tolerances used are determined by the CIE L*a*b* (CIELAB) formula. Colorfastness grade 5 is represented on the scale by two reference chips mounted side by side, neutral gray in color and having a Y tristimulus value of 12 ± 0.2. Colorfastness grades 4.5 to 1, inclusive, are represented by reference chips like those used in Step 5 paired with lighter neutral gray chips of similar dimensions and gloss