ABSTRACT
Nonporous substrates, unlike porous substrates, are impermeable to gasses and liquids. Metal, glass, and plastic are examples of nonporous substrates. These substrates do not absorb latent print residues. Latent prints remain on the surface of a nonporous item, which makes them fragile. Latent prints on nonporous substrates are especially vulnerable to obliteration by environmental effects such as wind, rain, temperature, and humidity. As with porous substrates, the water component of the latent print deposit evaporates over time. Cyanoacrylate (superglue®) fuming is widely utilized to affix latent prints to the surface of a nonporous item. The resulting prints are transparent or white in color and require the application of a fluorescent dye stain in order to make them more readily visible and increase contrast. In the accompanying laboratory exercises, latent prints are developed on a nonporous item using cyanoacrylate fuming and dye staining.
