SynopsisPABA (p‐aminobenzoic acid), a highly regarded sunscreening agent, has recently been shown to exhibit different absorption characteristics when applied to excised hairless mouse epidermis than when in dilute alcoholic solution. In the present study the cause of the differences was investigated.The results show that at normal application amounts, considerable quantities of randomly dispersed PABA micro‐crystals exist on the skin surface. The forward scattering spectrum of PABA on skin resembled more closely that of micro‐crystalline aggregates than that of PABA in sol