Homebrew PCBs

> am thinking of trying to make some silk screens for small volume 
PCBs
> and I think I need to be able to print a "positive" of my PCB 
pattern
> onto transparency in order to make the silk screen.
> 
> By positive, I mean that the copper tracks will appear white when
> printed on paper, and etched portions will be black. My PCB 
software
> does the usual "negative" print - copper tracks are black, etched
> areas white, but not the positive print.

Maybe I am wrong but I think you have positive and negative 
backwards?

I too use Ivex, to print to transparency for a positive to exposed 
my PCB's,  I personal have not done it but you can take a positive 
with photo film and make a negative which is what it sounds like you 
are wanting to make your silk screens.  I have been thinking about 
trying out screen printing to do text on the board, but have not had 
time to work with it yet.

Ben