The masks were worn by two white and three black volunteers for specific time periods. Using a comb packed with cotton wool, the hair was next combed at a specified time period ranging up to 6 days after removing the mask. The number of fibers recovered from the hair was counted under a stereomicroscope. In one study, the volunteers did not wash their hair after removing the mask; in the other study, they immediately washed and towel dried their hair. Results revealed that fiber loss followed an exponential decay process. Both types of fibers persisted in the hair for up to 6 days if the hair was not washed or up to 3 days if the hair was washed. Washing and towel drying the hair removed only approximately 80 percent of the fibers initially present in the hair. The type of fiber and type of hair did not affect the results, although an Afro comb was more efficient than a standard comb in recovering hair from black individuals. Figures, tables, and 3 references.