I do the same thing as the above person except, I put mine in a picture frame after. I used this black foam board thing from Hobby Lobby(less than $5). (?not sure what it is, but it's harder than foam and carboard. Here is a pic. This is only my 2nd craft show, so the set up is nothing fancy.
I also use a memory board too. YOu can make it, but I bought this one. Too lazy!