People are always asking how we store our mailart. Short of the classic "in a box" or "in a pile" methods, I do have a couple of other suggestions.
I am a thrift store junkie and you never know what will cross your path if you just keep looking. This wire rack was for Christmas cards I think. A quick spray of chartreuse spray paint...voila! It fits perfectly on the side of a bookcase.
I've also punched a hole in one corner of a bunch of cards and threaded them on metal rings. The hubby built this rack on the back of a door with wire shelving and I use shower curtain hooks to hold the rings. This system also works to hold zip-lock bags of collage bits.