Irreversible and Reversible Photobleaching of Dyes

Fifteen reaction steps have been demonstrated to occur in solutions (or other simple systems) of dyes and pigments Although no one compound has been proved to undergo all of them, they, and probably additional reaction steps, must be considered as constituting the primary processes for photochemical reactions of dyes. Some attempt has been made to suggest how these reaction steps may be related to irreversible and reversible photobleaching of dyes under conditions of technical importance.