How does one make one? Brass is my medium, but I can't understand how folks but the impressions in them. I'm sure it's similar to file stitching....

I always thought that the origonals were cold worked with small punches.
I know that at one time thimbles were made of leather.

These days I figure they a deep drawn and stamped. Tell the truth I really don't know.

File Stitching??

it's used in rasps to make the teeth, as opposed to a chisel it's more of a beveled punch (like your idea)

Shoot; I've seen a period illustration of thimblemaking; now to figure out where. I'd suggest looking in Diderot's encyclopedia, followed the the renaissance hausbuchs and then to disapper into my wife's history of textile working library.