Ideas for bottle cap art
Take a look here:
My aunt and uncle used them with mortar on the top of a wooden spool like the cable companies and telephone companies use. Then they put resin over the top or shellac to finish the top and used it on their patio when they had a fire or cookout in the back. She used the different colors to make designs on the top. It was pretty. You could do the same on wood for a garden decoration directly on a fence or as a stand alone "flower" etc.
Here are some great ideas https://www.pinterest.com/pin/81698180728342468/
Check this out: https://www.pinterest.com/pin/834784480910913159/ Maybe not art? But a cool idea to repurpose!
here are some ideas: