Fluorescence offers a very high contrast as well as high sensitivity under favorable circumstances. This discussion identifies the properties of light needed for fluorescent print detection and surveys the development of appropriate light sources. It concludes that lasers are costly in power and money, but the light produced is ready to use. In contrast, light from lamp sources is easy to obtain, but requires troublesome collecting, collimating, and filtering. Three types of lamps currently available for fingerprint use are examined: the Unilite, the Quasar, and the Lumaprint. Areas considered include reflectors, filters, and power sources. Methods to excite fluorescent materials at the crime scene are described. Photographs, tables, graphs, and diagrams.