Results of the study indicated that 55 percent of the ski masks showed evidence of test-fiber transfer sometime during the study, although the number of transferred fibers was rather small, ranging from one to three. Although the probability that a fiber will be recovered from the same side on which it was deposited is higher than the probability that it will be recovered from the opposite side, an examiner cannot conclude that fibers recovered in the laboratory from the inside (or outside) of an item were originally deposited on that side. During a hair and fiber examination, evidence is processed to locate and recover potential hairs and fibers. The processing of textile items often involves the combination of scraping and picking techniques. For ski masks and other head or facial coverings, the debris from the inside of an item usually is collected and examined separately from the debris from the outside of the item. The purpose of this study was to investigate the persistence of fibers on the inside and outside surfaces of ski masks during transit to the FBI laboratory and during evidence processing to see if separate examinations of the inside and outside of a mask are valuable and warranted. The study sample consisted of 20 ski masks seeded with 50 test fibers each on either the inside or outside only. The masks were then packaged, shipped, and processed according to protocol, and the final recovery location of the fibers was documented. Figures, table, and references