Emulsion

Emulsion

An emulsion is a mixture of two immiscible (unblendable) substances. One substance (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include the photo-sensitive side of Photographic film, and cutting fluid for metalworking. Emulsification is the process by which emulsions are prepared.

Most commercial photo emulsion products consist of either bichromated gelatin or a photopolymer such as bichromated polyvinyl alcohol (PVA) in suspension. It is often light brown in color and has the consistency of heavy syrup. Most types of emulsion have a short shelf life and must be refrigerated.