I love my unmounted stamps, and tried every storage solution I could think of that wouldn't cost a fortune. This is my method for storage and I think it works great. I take old CD holders (you can also buy them rather cheaply at a computer supply store) and remove the inside plastic that holds the CD. The unmounted stamps then lay perfectly inside. You can store them in a CD tower or stick them in a drawer. You can see exactly what is in each plastic cassette. Another tip: if you don't know how to make unmounteds stick to your acrylic block, just use Aleene's TACK-IT and you can stick and remove all you want. When you're done stamping, stick it back in its plastic holder. I don't even use a foam backing for my stamps. I just do my stamping on a computer mouse pad. It doesn't matter if the foam is between the stamp and the block, or on the bottom... it works the same way.