Integral Masking.

All modern negative, intermediate and internegative films have a characteristic colouring called integral masking, usually a red-orange colour. This masking is designed to correct for the fact that the dyes produced in the colour development process are not perfectly complementary to the spectral red, green and blue of the additive primary colours. Yellow dyes made this way are quite good, Magenta dyes usually absorbs some blue light they should transmit and Cyan dyes absorb some blue and some green light that they should transmit. These defects are not very noticeable when the dyes are viewed, for example in a reversal original, but when they exist in a negative image, they are copied and increased in significance by the copying process. The integral masks compensate for these defects in the dyes but because it results in a coloured base can only be used on negative or intermediate materials.