The wet collodion, also known as collodion process, is a technique associated with photography. A soluble iodide is added to collodion or cellulose nitrate and the mixture is applied on a glass plate. The glass plate acts as the negative. In the dark room, the glass plate is immersed in silver nitrate thereby forming silver iodide making it sensitive to light. The plate with the film is then exposed in a camera while it is still wet. Prints could be taken from the glass negative. This process of taking pictures was later replaced by dry plate process.