What is the fine-grained topic of the following text: These are samples you get every time you buy some makeup products, and something I can't bear to throw away but also never seem to use - so I gessoed the lot, and glued them onto the shelf with glue gel, then placed the rest of my prepped arty bits once thoroughly dry (and shaken to make sure things weren't going to come off). Only return the topic.
Upcycling makeup product samples into art materials