Homebrew PCBs

More random thoughts...

I was thinking about plated-through holes and how big fabs do them.
You drill, plate the holes, *then* etch.  They use a tin electroplate
as the mask.  Can we do something similar?

The idea:

Drill and electroplate the pcb.

Use a standard photomask, but in negative - expose where you want
copper to stay.  Develop.  Not sure if TT would stand up to the tin
plating.

Immerse in "Liquid Tin" to tin-plate the copper that's going to
remain.

Strip the mask and etch the board.