I like to use finished canvas frames, which are available in a variety of sizes.
Any means of fastening the inchies is allowed.
My first pictures were glued together, until I realised the potential of the small super magnets!
I had recently purchased some magnets and wanted to try them out, so I sewed small magnets in the inchies and fastened a counterpart on the backside of the canvas frame.
In this way I can change my picture easily any time without nasty glue residue.