Amido Black is a dye that is highly sensitive to the protein compounds found in blood. Amido Black is the perfect choice when attempting to recover weak or practically invisible shoeprint or latent fingerprint impressions. It may be used on porous and non-porous surfaces. The reaction product is a strong blue/black color, and it is best suited for use on light-colored surfaces permitting good visual contrast. Amido Black Solution is supplied in a pump spray eliminating any advance preparation prior to use. When stored at room temperatures, the solution offers a shelf-life of up to one year. While Amido Black is non-flammable, it is corrosive and will stain many surfaces.