ABSTRACT
In this digital age, many of the objects we handle in our daily lives are nonporous. Most items are manufactured from metal, plastic, and glass. These surfaces are considered nonporous: not permeable to gases and liquids. Examples of nonporous items include cell phones, drinking glasses, plastic bags, and vehicle exteriors. When a fingerprint is deposited on a nonporous substrate, the matrix does not penetrate the surface. Over time, the water in the fingerprint residue evaporates, leaving behind the water-insoluble components (lipids, waxy compounds, etc.) and the components that do not evaporate with the water (amino acids, sodium chloride, urea, etc.).
