Layering sunscreen with facial makeup enhances its sun protection factor under real-use conditions

Visualization of reflectance, transmittance, and application amount distribution of the cosmetic foundation layer on skin

We developed a method for visualization of makeup finishing with structured lighting. By analyzing images with a sequence of projection patterns, reflectance and transmittance of the cosmetic foundation (FD) layer were extracted as spatial maps using the difference between the light spread of bare skin and made-up skin. The spatial maps reflect conditions and distribution of applied FD under real situations. By calibrating the relationship between optical properties and the amount of FD applied, the application amount distribution was also estimated. Additionally, we proposed approximation formulae to estimate the above values without images of bare skin. These formulae provide good agreement with the original formula for reflectance.

Estimation of reflectance, transmittance, and absorbance of cosmetic foundation layer on skin using translucency of skin

We developed a method to estimate the reflectance, transmittance, and absorbance of a layer of cosmetic foundation (FD) applied to skin from the reflectance of bare skin and FD applied to skin under two measurement conditions using the translucency of skin. Conversely, using the relationship between the applied amount of FD and the reflectance of the FD layer, the applied amount could be estimated. These values could be measured stably regardless of the similarity of reflectance and color between bare skin and made-up skin. The measured values were taken from actual skin, which satisfies the condition of actual usage.