Film Identification Resources

Duration:

2 minutes, 2 seconds

The polarization test is a simple non-destructive method to identify the types of film in your collection. This test involves the use of a simple tool which relies on the properties of light as it travels through two pieces of polarized film. This tool can be used to help you identify a piece of film as polyester or cellulosic, but it cannot be used to differentiate between the cellulose acetate and cellulose nitrate films. This identification is important because all cellulosic film requires cold storage and most polyester are stable in a normal archival environment. Here is a brief demonstration on the use of this tool.