One of the most important attributes of Make-up Base is its covering power. However, in the evaluation of covering power on Make-up Base no instrumental methods are available and recourse must be had to panel testing.
The subjective appraisal of the covering power on Make-up Bases (24 samples) was made by 13 specialists, the observations were analyzed, and a multiple regression equation was drivel.
The following results were obtained.
(1) A multiple regression equation for estimating the covering power on Make-up Base was drivel, taking as variables S and ΔE which are related to the shear strees and the color difference between skin color itself and the one seen through Make-up Base film applied.
The multiple correlation and contribution factor were 0.96 and 0.92, respectively.
(2) This means the estimated covering power by the present regression equation agrees fairly well with that obtained by observation.