After major brain-frying efforts, I got a working solution to this spot color thing. I'd be pleased to know if it's similar to the "right" way to do it, if there exists such a thing.

I set up a spot color plate by using one of the process plates (happened to be magenta)to be the home for my one spot color. I created a spot color that was 100% magenta, letting this represent full intensity of my spot color ink. I then developed a series of tints based on this spot color, and "painted" any spot color areas with them. I used only fills, transparency worked sometimes but not consistently, producing some weird looking errors (astigmatic, squeezed objects in the file)Black was used normally, 100% as well as fills, on the black plate, of course.

Keeping everything stacked up correctly, I printed to file only the two plates, black and magenta. I had to print each to it's own file by turning on one and then the other separation: attempts to make a PRN file with two or more pages produced an error message(printing to a PostScript printer). The idea is to use the magenta plate as the spot color separation.

I renamed the resulting prn file to eps, since no imagesetter on earth recognizes a PRN file(thanks, Sean). At this point, I then converted the eps files to pdf, since the printer said he couldn't get them to output correctly (STILL!) as eps files. So far it seems to be working.

Only question is: did the black trap the (blue) spot color correctly ?(I turned off the layer with the black on it and checked "visible layers only" when outputting the magenta plate, so there would be no areas "knocked out" behind the black, just in case)

What this gives me is the ability to produce jobs where I use limited colors, and have control over exactly where and in what tint the spot color appears...not just a solid object "stuck on" the page, but almost like painting with a limited palette.

Is this the easiest way to do this? Or did I just spend a day and a half inventing a real elaborate version of the wheel?

David