Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Robert Blumer <bob@...> wrote:
>
> Tom, I would like to know if what you have is positive resist or
negative?
> I  like the positive to work with in the home because of the pcb 
> programs and
> Ink jet printers. ( I use 2 prints stacked to get it black enough)
> I used KPR resist for a number of years for all my hobbies, Ham Radio 
> and R/C Airplanes.
> I sprayed some and dip some and found the best for me was an old 78 rpm 
> record player
> and I just used an eye dropper to put some on the board in the center 
> with it spinning
> this gave me the best results with it.
> regards
> Robert Blumer
> Billings MT
> 

Robert,  

All dry film photo resist is negative acting. It also require less UV
power to properly expose. I use film negatives that are photoplotted
to expose the dry film. My reject rate is almost zero with this
process. Photographic films will always give the best results.

I posted some information about a new liquid photoresist a few weeks
ago so maybe you should search for that information if you like the
liquid type of resist. It's water based, easy to use and is also 
negative acting.

Tom