Many forms of 3D printing involve photochemical transformations, including SLA, DLP and 'PolyJet'. This topic is for sharing resources for light-activated materials chemistry.
One of the challenges to beginners in this field is simply finding the right terms: 'photoresist', 'photopolymer', and 'photocurable resin' typically refer to the same general chemical principles, although they are used in different applications.
Wikipedia has a decent introduction to various mechanisms of photoactivation:
Scotten Jones has also written a nice chapter on photolithography, which includes a more historical perspective on the development of photoresists for the integrated circuit industry.
What resources have helped you learn about photochemistry? What information is lacking?