JAMES KING-HOLMES / SCIENCE PHOTO LIBRARY JAMES KING-HOLMES / SCIENCE PHOTO LIBRARY
Magnetic fingerprint powder. An applicator 'brush' is used to apply magnetic fingerprint powder to fingerprints on a polystyrene ceiling tile - a surface from which it is impossible to get fingerprints by ordinary means. The 'brush' consists of a magnet carrying thousands of tiny iron flakes. An organic coating on the flakes makes them stick to the greasy residue in a fingerprint as the brush passes over. Excess powder is removed by magnetism. Because the brush lacks bristles, which would smear or erase the delicate ridge lines in the prints, the technique gives sharper results and works on difficult surfaces like plastic bags and magazine covers.
Model release not required. Property release not required.