Individual identifying characteristics that are generated in the manufacturing process and during normal wear-and-tear may be recognized on denim trousers and in photographs of the trousers. The characteristics may include folds, creases, and puckering, which manifest as high and low areas (“ridges and valleys”) along and adjacent to the seams and hems. As the trousers are worn and washed over time, the visibility of ridges and valleys is amplified through abrasion of the ridges, resulting in a loss of dark dye and marked tonal brightening. Given sufficient abrasion, even small ridges may exhibit sufficient contrast against the dye-rich background to be recorded on bank surveillance films, permitting comparison with trousers recovered from suspects. The principle behind photographic comparisons is the same as that behind comparison of fingerprints, footwear impressions, bullets, firearms, or any other kind of physical evidence -- the principle of individualization. The article discusses application of this technique in a case involving a series of bombings and bank robberies in Spokane, WA. Figures, references