Until 1950 inherently unstable cellulose nitrate was used as the carrier for films. In addition to the deformation and distortion of information by chemical decomposition, this material burns explosively and cannot be extinguished. This is why there are strict regulations for the storage of nitrate films. Such instability has been the cause of the loss of 80% of world holdings up to 1930 and 50% of holdings from 1930-1950. In the race against incessant decay, film archives all over the world are striving to redeem what is left of historical cinematographic heritage by recopying. >> More