This is a general purpose methanolic silver nitrate solution. A convenient spray head permits application in the field or laboratory. The surface being treated should be sprayed lightly and evenly. After treatment, the article should be permitted to dry completely, preferably in the dark (approximately 2 minutes). After drying, illuminate the treated surface with high-intensity light (sunlight) or SIRCHIE®'s SNA4 Silver Nitrate Accelerator Lamp. Fingerprints will appear as dark grayish-brown images and should be photographed before the article background develops.