I agree that felt would be a very bad idea. ReLoad uses some crap called Cordura® I would guess that they would sell you the material if you wanted to go over to the shop, they seem like very cool people over there. either that or go down to Fabric Row and start asking the people in the shops what they would recommend, you may find a new material that no one else has thought of and that would make your bag pretty rad. either that or just put some glue and glitter on the back.