HENNA AND LAWSONE SORPTION BY WOOL 361 Figure 1. Wool felts dyed with lawsone at various pH values. 1, pH 3.0 2, pH 4.0 3, pH 4.5 4, pH 5.0 5, pH 6.0 6, pH 7.0. Dyed at 50øC for 30 min. cording to their intensities from 0.1, the lightest, to 20, the most intense. The numbers mean the same for all three colors, so that a combination of the 0.1 red slide and the 0.1 yellow slide, for example, gives 0.1 units of orange, one of three possible secondary colors, orange, violet, and green. Results are expressed in the manner shown in Tables I to III. The matching series column designates the values of each of the primary colors used to make the match, and the color developed column expresses what is actually seen by the eye. Thus for the second row in Table I, 0.1 units of blue Table I Effect of Dyeing Time on Colors Developed with Lawsone and Henna at 30øC and pH 4.5 Lovibond Tintometer Matching Series Color Developed Hunterlab Colorimeter Time (min) Red Yellow Blue Red Orange Gray L a b Lawsone 30 11.0 9.9 0.2 1.1 9.7 0.2 42.3 24.2 13.2 50 11.4 9.9 0. l 1.5 9.8 0.1 -- -- 60 11.7 9.9 0.3 1.8 9.6 0.3 42.0 24.5 12.9 90 11.7 9.8 0.2 1.9 9.6 0.2 41.9 24.9 13.2 Henna Yellow 30 4.7 8.7 1.2 4.0 3.5 1.2 44.8 11.4 12.5 60 5.7 9.7 1.4 5.0 4.3 1.4 43.9 11.4 ll.7 90 6.7 10.0 2.2 3.3 4.5 2.2 45.5 10.6 ll.9

362 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Effect of Temperature on Colors Developed with Lawsone and Henna at pH 4.5 and 30 Min Dyeing Time Lovibond Tintometer Matching Series Color Developed Hunterlab Colorimeter Temp øC Red Yellow Blue Red Orange Gray L a b Lawsone 15 10.0 9.6 0.1 0.4 9.5 0.1 53.4 25.7 12.5 30 11.0 9.9 0.2 1.1 9.7 0.2 42.3 24.2 13.2 40 12.6 9.9 0.2 2.7 9.7 0.2 41.9 26.4 13.0 50 13.2 9.9 0.2 3.3 9.7 0.2 40.1 25.2 11.2 Henna Yellow 15 4.5 7.1 1.0 2.6 3.5 1.0 50.7 10.8 14.5 30 4.9 8.1 1.1 3.2 3.8 1.1 44.8 11.4 12.5 40 6.4 8.5 2.2 2.1 4.2 2.2 43.8 11.7 11.9 50 6.6 9.6 2.4 3.0 4.2 2.4 41.0 11.0 10.2 combine with 0.1 units each of yellow and red to give 0.1 units of gray. The remaining 9.8 units of yellow combine with 9.8 units of red to give 9.8 units of orange, leaving 1.5 units of red. The Hunterlab colorimeter measures reflected color photometrically. Colors are recorded on the L, a, b scale. The color values are relative to the absolute value of a perfect, white diffuser, as measured under the same geometric conditions. L measures the lightness, and varies from 100 for perfect white to zero for black, which approximates to eye evaluation a measures redness when positive, gray when zero, and greenness when Table III Effect of pH on Colors Developed With Lawsone and Henna After 30 Min Dyeing Time at 30øC Lovibond Tintometer Matching Series Color Developed Hunterlab Colorimeter pH Red Yellow Blue Red Orange Gray L a b Lawsone 3.0 13.1 9.4 0.4 3.7 9.0 0.4 41.1 26.3 12.2 4.0 14.2 9.8 0.3 4.4 9.5 0.3 41.5 27.7 12.7 4.5 11.0 9.9 0.2 1.1 9.7 0.2 42.3 24.2 13.2 5.0 13.4 8.7 0.2 4.7 8.5 0.2 41.9 26.9 13.2 6.0 11.4 9.7 0.0 1.7 9.7 0.0 45.0 26.5 15.8 Yellow 7.0 5.7 8.0 0.2 2.3 5.5 0.2 58.5 18.5 21.7 Henna Yellow 3.0 6.4 9.6 3.3 3.2 3.1 3.3 40.1 8.6 8.5 4.0 7.3 10.0 4.0 2.7 3.3 4.0 38.9 8.8 8.0 4.5 7.6 10.0 4.0 3.6 2.4 4.0 44.8 11.4 12.5 5.0 7.1 10.0 3.0 2.9 4.1 3.0 43.5 9.5 10.7 6.0 7.0 9.5 3.2 2.5 3.8 3.2 44.7 11.2 11.8 7.0 6.4 9.2 2.0 2.8 4.4 2.0 46.0 12.2 13.6