Empty frames that fit the sizes of the canvases. There are two basic sizes of canvases, so they would work for the painted and unpainted canvases. Having them empty would provide more versatility in how we use them. A plain wooden one, and a fancier gold one would be really nice to see.
Frames for the flat canvases would probably be easiest, but framed versions of the top down paintings would also be nice to have.