I made a Hogwarts themed bag for myself. It is made of heavy black cotton fabric. The inside is lined with Gryffindor red and gold with several pockets. The short straps are lined with the same fabric. These are all iron-ons.
back with pockets and iron-ons of Dumbledoor's Army, Gryffindor and the Order of the Phoenix:
I'll be taking it to the HP Terminus conference in Chicago next month.