Homebrew PCBs

----- Original Message ----- 
From: "David Hopkins" <davhop@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, October 11, 2008 3:32 AM
Subject: [Homebrew_PCBs] Reversing film.


> Gentlemen,
> For over thirty years I have been making PCB boards using a
> photographic method.
>
> The pre coated board I have been using is -ve acting.
>
> This requires a negative to be produced from the +ve computer
> generated artwork. For many years I used an orange (UV opaque)
> material made by 3M.
>
> This was taken off the market and I switched to an AGFA
> Printon  Ortho daylight film. This was far superior than the orange
> film however the section of AGFA that made this film went out of
> business a couple of years ago.
>
> Try as I might I can't find a replacement for this film.
>
> What I need is a method that can make a high contrast UV opaque
> negative from a positive printed on cleat plastic.
>
> Anyone have any suggestons?

I used to get my positives made by a litho plate maker, from my 2:1 
printout. I remember them making a negative first, as I got one back with my 
positive.

Leon