MEASUREMENT OF HAIR LUSTER 293 Table III Color Values as a Function of Position, Viewing Angle, and Viewing Aperture of the Sample L8 a a •: b •: Sample position Sample viewing angie Reading reproducibility • Sample viewing aperture 2 Vertical 23.04 _+ 0.68 4.04 _+ 0.28 4.72 + 0.16 Horizontal 22.48 _+ 0.62 4.10 _+ 0.16 5.13 -+ 0.21 2 ø 23.75 _+ 1.19 3.82 -+ 0.33 4.95 + 0.44 10 ø 23.59 -+ 1.19 3.87 -+ 0.33 4.76 _+ 0.42 5 x 10 mm 22.72 _+ 0.02 3.35 -+ 0.03 3.85 + 0.03 20 x 10 mm 21.68 _+ 0.02 4.28 _+ 0.03 5.41 + 0.03 5 x 10 mm 23.59 -+ 1.19 3.87 -+ 0.33 4.73 ñ 0.42 20 x 10 mm 21.85 _+ 0.31 4.07 _+ 0.17 5.09 -+ 0.38 Operation conditions not specified by second column were: horizontal sample position, D65 illuminant, 10 ø viewing angle and 5 x 10-ram viewing aperture. Averages and estimated standard deviation among a set of ten measurements. Dark brown hair (D-B). • Hair tress remained in the same position during the readings. 2 Hair tress position was changed during the readings. Table IV Color Values as a Function of Color, Texture, and Geometry of the Sample, Including and Excluding the Specular Component Sample Specular component L* a* b* Smooth surface: a slide with black "nanquim" dye Cylindrical surface: capillary tube filled with "nanquim" Cylindrical surface: black hair Cylindrical surface: black hair treated with brilliantine Smooth surface: smooth green paper Irregular surface: wrinkled green paper Included 25.95 -0.05 0.24 Excluded 1.12 0.10 -0.96 Included 19.89 - 0.08 - 0.62 Excluded 19.06 - 0.08 - 0.76 Included 18.37 -0.05 -0.84 Excluded 18.00 0.02 - 0.91 Included 20.67 -0.04 -0.96 Excluded 20.17 0.02 - 0.99 Included 46.75 - 52.38 13.15 Excluded 42.75 - 65.83 17.51 Included 46.28 - 50.84 12.59 Excluded 45.28 - 52.80 13.28 Operating conditions: horizontal sample position, D65 illuminant, 10 ø viewing angle, and 5 x 10-mm viewing aperture. Quintuplicate measurements. the specular component had a significant influence on the color parameters when the surface was smooth. However, for cylindrical samples, this difference was in the experi- mental error range. This means that for hair samples, the specular component does not correlate with luster. Current and adapted holder. As described above, an adapted holder was built in order to improve alignment and to avoid entanglement among hair fibers during the measure- ments, since a reduction in luster occurs when fibers are not sufficiently aligned (7). Table V shows the parameters of average values obtained with the current holder and the adapted holder for the CIELAB and FMCII systems. The L* value decreased by approxi-

294 JOURNAL OF COSMETIC SCIENCE Table V CIELAB System Parameters L*, a*, and b* and FMCII System Parameters X, Y, and Z, Obtained for Three Dark-Brown Hair Tresses (D-B1, D-B2, D-B3 ethyl ether/8 h) With Current and Adapted Holder CIELAB FMCII L* a* b* X Y Z Current holder D-B1 Adapted holder D-B1 Current holder D-B2 Adapted holder D-B2 Current holder D-B3 Adapted holder D-B3 Average Deviation % Deviation Average Deviation % Deviation Average Devmtion % Deviation Average Deviation % Deviation Average Deviation % Deviation Average Deviation % Deviation 23.03 3.96 5.46 3.88 3.80 3.23 0.35 0.11 0.16 0.10 0.10 0.08 1.52 2.88 2.89 2.59 2.66 2.56 21.14 3.89 5.34 3.35 3.28 2.71 0.20 0.16 0.33 0.06 0.05 0.04 0.98 4.03 6.13 1.74 1.67 1.33 23.38 3.78 4.87 3.97 3.91 3.36 0.40 0.18 0.18 0.13 0.12 0.01 1.75 4.99 3.89 3.25 3.10 2.87 20.79 3.84 5.47 3.25 3.19 2.61 0.20 0.12 0.24 0.06 0.05 0.02 0.98 3.21 4.41 1.76 1.64 0.91 22.88 3.80 4.03 3.82 3.72 3.22 0.47 0.15 0.31 0.14 0.03 0.09 2.08 4.07 7.59 3.73 3.69 2.81 21.31 3.72 4.99 3.38 3.32 2.81 0.44 0.16 0.22 0.12 0.12 0.11 2.11 4.26 4.49 3.62 3.57 3.94 Operating conditions: horizontal sample position, D65 illuminant, 10 ø viewing angle and 5 x 10-mm viewing aperture. Averages and estimated standard deviation among quintuplicate measurements. CIELAB system parameters: L* (lightness coordinate), a* (red-green coordinate), and b* (blue-yellow coordinate). FMCII system parameters: X (coordinate x), Y (coordinate y), and Z (coordinate z). mately 10% with the adapted holder, which means a sample darkening in relation to the data obtained with the current holder. The a* and b* values obtained with the adapted holder were in the error range of those with the current holder. The reproducibility was in the same range for the CIELAB system with the adapted holder. However, for the FMCII system, the values of X, Y, and Z decreased by approximately 12% to 22%, and the reproducibility decreased by an average of 25% (current holder deviation of 3.00% and adapted holder deviation of 2.24%). The adapted holder was used throughout the next experiments. COLOR PARAMETER EVALUATION Diffuse reflectance measurements were performed on the samples treated as described earlier in Methods. The following parameters were obtained: for CIELAB: L*, a*, b*, DL*, DC*, and DE* and for FMCII: X, Y, Z, DL, DC, and DE. A reference (zero- difference) value was obtained from the average value of L*, a*, b*, or X, Y, Z of the quintuplicate measurements taken from ethyl ether 8-h treatment on the hair tress. Values of color differences (DL*, DC*, DE*, and DL, DC, DE) for the two systems were comparatives between the reference values and the respective values for each treatment.