SD card holder for 3D/Prusa printer

I was starting to get a pile of SD cards going and was having some difficulty finding older projects to re-print. Several have posted some holders for the actual SD cards themselves, but I happen to have a box of #1 coin envelopes (pictured) and I wanted to use those because, as you can see, I can actually write on the envelope to see what's on the card inside. Also, and this is a personal thing, I buy 64MB and 128MB cards because for one thing they're fairly inexpensive, and because they only h