It's not just paste-up materials, but graphic arts supplies of all sorts that are long gone. CAD (Computer-Aided Drafting) has made draftsmen's tools totally obsolete. I have a pair of triangles and a decent compass and divider set that I use in my pottery studio, and I guard them with my life. If they were lost, finding replacements would not be easy. The go-to source used to be college bookstores, but nobody teaches manual drafting anymore.