Background: The efficacy of skin care products dependson the time and dynamics of their absorbance by the skin,and its spatial distribution on the skin. Regular scrapebasedmethods may depend on the operator and are destructiveand invasive in nature. Here, we describe a novelmethod based on non-contact optical measurements totrace the location and dynamics of skin care products onthe skin.Methods: We use fluorescent silica colloidal particles ofmicron sizes at a rather small concentration as non-invasivetracers. As an example of skin care products, we use twobase materials: either glycerin or vaseline. A mixture of eachproduct with fluorescent particles is applied on human skin.The amount of fluorescence is monitored by means of afluorescent spectrometer. The scraping method is used tocompare with the spectroscopic measurements.Results: Fluorescent tracers make the skin care productvisible under UV light. This allows obtaining an optical imageof the spatial distribution of the product on the skin. Thequantitative data of fluorescence are well correlated with thescrape data. Comparison of the difference in the spectraland scraped mass data reveals the details of accumulationof the skin products in skin cracks and crevices.Conclusion: We described an efficient non-invasive benignmethod to quantify dynamics and to perform mapping ofemollients and humectants on the skin.