"Tim Wescott" wrote in message
...
I have seen (held in my hands, actually), metal parts that are made by
etching thin steel with acid (presumably after printing on a resist).
It's great stuff for making optical stops, encoder wheels, and other
things where the worst that the metal has to resist is a stream of
photons smacking into it.

The steel in question appears to be either stainless steel or tin plate,
dead soft, and is maybe 5 or 10 mils thick.

What's the processing called in the industry? What sort of shop should I
direct someone to look for in their yellow pages or their Thomas
Register? What sort accuracies can one expect, and setup costs, and
fabrication costs?

http://en.wikipedia.org/wiki/Photochemical_machining
http://www.fotofab.com/about.php

jsw