Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, twb8899@y... wrote:
> 
> The negative-positive issue seems confusing at times but here's how 
> it works. Screen printing requires that the image being printed must 
> be opened up or "washed out" from the screen emulsion. 
> 
> Exposing the screen emulsion with a film positive consisting of black 
> lines representing copper and clear areas representing the areas of 
> copper to be etched away will get the job done. 
....

I feel like a dope. I went back to the start of the thread and re-read
it, saw that the original poster -did- have it backwards with respect
to pos/neg, and I had forgotten that this was -not- about using screen
print photo emulsion as a direct resist, it was about making a screen
to lay down etch resist.

Steve