I am currently printing my positives on film using Accurip, but I started out using the Epson Driver itself on my 3880. To print on my Fixxons film the best results were using the Ultra Premium Presentation Paper Matte media setting, this was recommended to me by Epson support. The ink definitely needs to be the Matte Black. The media and ink settings were the most important. They generated a pretty solid black. In the Epson driver it is possible to adjust ink density, but I never messed with that. The ink did not appear to me to be quite as black as what I was getting with my dye ink in the 3000. But it worked great burning screens with my workhorse MH exposure unit! I stuck with 1440 x 720 resolution and never really used anything higher. My type set in Illy was at 600dpi and it had very sharp edges.
Finding the right media setting was the trick to keep me running until I got a RIP.
