Sometimes you need a very thin metal shim. Quite often, these shims are very hard (impossible!) to find at your local hardware store. Here's a way to get some nice stainless steel shims for practically nothing.
I use a double edged safety razor to shave. They're incredibly cheap, last me a few months each and give a closer smoother shave than any twelve bladed monstrosity out there. When a blade is no longer useful for the purpose, it has to be disposed of. This is often a pain, as the blades are still very sharp and can easily slice their way out of garbage bags and end up where they shouldn't. (in your foot, the neighbour's dog, etc)
So, I hang on to them and look for ways to repurpose. One day I found I needed a tough steel shim, here's how I made it.
NOTE: Before you start messing with these blades, make them dull. I rub them at a perpendicular angle across 400 grit emery paper. This renders them mostly harmless.
Here's what I use:
Dremel with a diamond coated wheel. These are super cheap. I buy them in 4 packs from a discount hardware place for $2.99.
A strip of very sticky duct tape. I'd suggest Gorilla Tape, as it's got double the adhesive of anything else out there.
A dulled razor blade. Darn near free. I buy 5 packs for about $3.00 and they last me at 6 months or more.
EDIT: Just got a new batch from Amazon. 25 blades for $9.50. At my current rate of usage, I'm covered for about four years worth of shaving.
Step 1: Cutting It Up
Stick the dulled razor blade firmly into the adhesive on the tape. You may find it useful to tape the tape down, so it doesn't move around on you. Use the Dremel with the cutoff wheel at a slow/medium speed to carefully cut out what you need from the blade. Just the weight of the tool is more than enough to accomplish this.
We want to avoid heat buildup here, as the adhesive will soften if it gets warm and tiny shards of metal could be flung around the room at insane velocities. If you see the metal moving around, or if you've cut all the way through the tape, STOP. Relax. Proceed.
Step 2: What You Get
What you end up with are tiny metal shims in whatever size and shape you want. I find it easiest to remove and handle these things with a good pair of tweezers. Be sure to store the extras/leftovers somewhere safe. While the blade has been dulled, it's still made of tough, thin, steel and will easily puncture skin.
Hopefully this has been educational for you. Have fun, be careful!