This turned out to be a fantastic recycled art project! We collected all kinds of bottle caps for months and the large hard cardboard inserts from library shipments then added imagination. Participants were told to draw a large picture with a marker and fill it in with a variety of bottle caps. Most were plastic but a there were also metal caps at each table. The plastic caps stick easily with school glue but the metal ones need hot glue to be sure they will hold. At the end we decorated the whole thing with sequins from our jar of left-overs.
This is a great use for something that our recycling company cannot take. Wonder if they melt? Ah, another project idea.