Celluloid is a hard, unstable synthetic substance once used for films. It is composed of gun-cotton and camphor and is moulded to the desired shape by heat. Celluloid was formerly extensively used as a substitute for ivory, bone, hard rubber, coral, etc, having a close resemblance to these substances in hardness, elasticity, and texture. It was used for buttons, handles for knives, forks, and umbrellas, billiard-balls, piano keys, napkin-rings, backs to brushes, etc. It can be variously coloured, and was known to be dangerous on account of the readiness with which it takes fire, even while being widely used. Research Celluloid