Celluloid is a material made by plasticizing nitrocellulose with the assistance of camphor. This substance was first invented in the 1800s as a replacement for ivory and bone, and its uses later greatly expanded, perhaps most notably into the world of film. By the 1950s, however, the disadvantages of celluloid had led to a general decline in the market for the material, and today it can be challenging to find.
Nitrocellulose is made by exposing cellulose to a nitrating agent. When plasticized with camphor, the resulting material is very easy to mold, shape, and handle. However, it has a very distinct disadvantage: it is highly flammable. Celluloid is so flammable that it will continue to burn even when dunked in water, making it a serious fire hazard, as one might imagine. It is also not very light stable, decaying rapidly when exposed to light.
Although flammable, celluloid is also extremely durable, making it useful for a wide range of tasks. In corsets, for example, the material could help hold a form without rusting, as was the case with metal stays, and the flexibility of celluloid also allowed for some freedom of movement on the part of the wearer. Celluloid was even briefly used to make very durable clothes, although a few unfortunate accidents quickly put a stop to this practice.
This substance was first marketed as Parkesine and later as Xylonite. The term “celluloid” was originally a trademark, taken out in 1869, but thanks to trademark dilution, it came to be used more generally to refer to plasticized nitrocellulose, rather than to a specific brand of this product. Originally, celluloid was used to make things like stays for corsets, pool balls, and a variety of other objects once made from bone; when its potential as photographic film was realized, celluloid production took off in a major way.
Well into the 1940s, films were produced on celluloid. At the time, this turned out to be quite dangerous, as projection room fires started easily and were hard to put out. In retrospect, the widespread use of celluloid was also a great shame, because the film yellows and cracks with time, and as a result, many great films have been lost to history. Today, acetate and polyester are used to make film, but celluloid still has an iconic place in the film world, thanks to its role in early film production.