Physical Processing Methods
The most common fingerprint processing technique is the application of black fingerprint powder to a surface with a fingerprint brush. “Dusting” a crime scene or item of evidence with fingerprint powder is a physical processing method rather than a chemical reaction. Powder granules adhere to the wet and oily components of latent print residues when the fingerprint powder is applied with an applicator such as a fingerprint brush. Powders are a low-cost and efficient method for developing fingerprints on nonporous substrates.