The backing I went to a craft store that carried jewelry supplies (Hobby Lobby in my case) called bezels. [link]
I also got some ice resin. [link]
Looks like this. The designs inside I drew and colored myself in my plain ordinary sketchpad. I cut them out, put them into the bottom of the bezels and then poured the resin on top and left to dry. Make sure when you do the resin to do it on newspaper. Does that help?