But you can't enjoy a negative. You need a positive image. To get it, we pass light through the negative and onto photographic paper. And the exposure of your negative upon photographic paper is called printing. Between the emulsions are protective interlayers and all of these layers together aren't as thick as a human hair.
Reversal films contain three separate color pictures in three layers on one base.
After processing, the top layer has a positive yellow image of everything in your picture that is yellow or needs yellow in its finished color. The three layers, when viewed together, form a complete color transparency with infinitely varied and delicate shades. The top emulsion layer of negative film is sensitive to blue light. Beneath this layer is a filter coating which stops the blue light from penetrating deeper. Moreover, a negative's color will be opposite that of the subject.