Someone who wants to sell there printing services could definitely post a listing saying so and receive inbound over nostr:npub15dc33fyg3cpd9r58vlqge2hh8dy6hkkrjxkhluv2xpyfreqkmsesesyv6e. Shipping info would have to communicated manually by the person requesting the prints as we currently don’t handle shipping information, but we’re working on an implementation of this to automate the process.