" fired this volley in news:25adcaf7-
:

010 How about masking it and then etching . A wood trough lined
with plastic would work for something to etch it in. Look on the
internet for etching solution. Muratic acid and peroxide is one
solution you will find. Also vinegar , hydrogen peroxide and salt is
another. Just do not do the etching near your tools.


Woof! I've done 19"x19" PCBs in a home-made etching tray, but DAMN! 80
inches? I'm also thinking if I get any undercutting, it'll condemn the
'spring' after a few tens of thousands of flexes, and I need millions
from this (another reason for the length vs. travel).

I've seen .002" copper under-cut (badly), so I suspect .010 might, too.

Lloyd