I had a correspondence with Dr. Gaddy some years ago concerning photo sensitivity of CC. He was of the opinion that CC is not photosensitive and does not fade in sunlight. None of the compounds in the film should be photosensitive. Remember, the color seen is based on film thickness.

I'm going to step out on a limb just a bit here and opine that since most CC is coated with something the fade issue is likely to be photosensitivity of the coating.

Other opinions welcome.

DDA