Don't know if anyone sells this - we're looking for single conductor flat wire. So if you have 22AWG wire and smashed it with a hammer until it was flat, that's what we're looking for, without the hammering. Thanks!
Have you considered battery tagging strip. A flat tin or nickel (I think) coated thin strip. It's spot welded on to cell terminals to make up battery packs. It comes in several different thicknesses.
I Googled it and couldn't find an easy hit. I can find a retailer if interested as we use it at work. It is however uninsulated so may need covering in a heat shrink material.
It depends on how much you need as feeding into heatshrink covering maybe a bit of hassle if you require many metres of the stuff.
You could also possibly take a reel of 22SWG to a local workshop and see if they can flatten it through rollers. A straight forward procedure.
Rectangular wire is sold for magnets. Here's just one vendor: http://www.swigercoil.com/magnetWire.php
Of course, ordinary production material will have insulation -- the absence of which is a criterion not mentioned in the original post.
Bare wire can be passed through rollers to get it as "smashed" as you want, but it will work harden. Passing though a flame will anneal it.
So that this doesn't end up a guessing game, what thickness, what width, and what quantity of uninsulated copper do you want? What are you using it for?
Edit: PCB repair kits have uninsulated flat wire. Here is one vendor that sells 5 mil x 30 mil spools: **broken link removed**
John