I’ve said it before on this forum…I taught jewelry making and metal smithing for 15 years or so and always cautioned my students “diamonds cut diamonds, files cut files.”
I NEVER allow my files to touch each other. When I saw Eric’s post I actually slightly gasped.
I do more metalwork than wood work and the drawer that I have my metal working (pewter only) files in, I did make separators to keep them from touching. My wood rasps and files are in a toolbox drawer isolated from each other by the sleeves I mentioned (but I’ll need more when my new rasps arrive). Files for my silver work are in a separate drawer, not touching each other. I lay cloths between layers of files when I have to lay one on top of another.
You do not use files (and some other tools) that you use on pewter and aluminum when working silver (or other precious metals). I actually have a separate work bench and area for my pewter work, it is also my firearms bench.
For the new rasp sleeves I was thinking using some manila folder paper, making a sleeve by stapling one side. Not the most elegant or sturdy solution but they would last awhile. I don’t have room for visible racks to store them in and I don’t use them that often either.