So, one thing I continually bump into is there's not enough time in the day to do all the things I want to do with my photography. And I try to ask people who are working in similar areas for recommendations on equipment and technique.
I have Epson 4800 and 9800 printers, and they are fine printers indeed. I do many a digital color or black and white print with them and have been very pleased with the results. The problem I ran into with these two printers occurred when I started trying to produce digital negatives for palladium printing with high key images. A negative for a mostly white image consists of large swathes of solid ink lay down on Mitsubishi Ultra Premium Pictorico film. While studying the prints I noticed that there were uniform horizontal varying bands of light and dark (oddly the size of the print head seemingly) forming an undulating wave that was visible in the final print. I mentioned this to Mark Nelson and he replied he had seen this before and called the problem venetian blinds (putting a name to my pain). Not on all printers, and only in large, low contrast light areas of the resulting print (corresponding to areas of highest ink density in the negative). Interestingly Alain Briot mentioned that he had seen this density variation artifact in the shadow areas of some straight digital prints, but that the effect seemed transient.
This is not the same as a clogged head resulting in no ink from one nozzle and microbands appearing across the print. That requires a cleaning cycle. These are 1 - 1.5" bands varying dark to light and back again running parallel to print head travel. The effect is very subtle (but noticeable - someone else noticed it first in a print) similar to paper warped by moisture and wavy and showing shadows - except the paper is flat.
Mark mentioned in a moment of my deep despair that he had never seen this on an Epson 2200 (which I had just given to my friend Ken) - or an Epson 3800.
An Epson 3800 is a fine printer for generating digital negatives. I mentioned that already, I think. With a 17" wide carriage it can produce 16" x 20" negatives for large contact prints. One limitation of the Epson 3800 compared to the Epson 4800 is that there is no roll media support. I have to cut down the Ultra Pictorico roll material to size to feed into the printer. On the other hand, the Epson 3800 has a much smaller footprint that the Epson 4800 and can be considered a desktop printer (the Epson 4800 strains that definition). It is reasonably priced.
I use the Epson 3800 for straight digital prints also. It holds both Matte Black and Photo (Glossy) Black ink cartridges and will automatically switch between inks depending on whether you are printing glossy or matte surface paper. Ultra Pictorico is glossy. Some ink is wasted during flushing of the shared ink line so you don't want to switch inks say between each print but rather group your printing sessions if you go back and forth between media surface types.
The printer is a work horse and I'm very pleased with it.
Another feature of the Epson 3800 is that it outputs 16 bit files rather than 8 bit files - with the right operating system and driver. While it is missing on a list of pro-imaging printers that support 16 bit operation, it is on another list and I can confirm that the MacOS X 10.5 driver has the option for 16 bit printing. Mark Nelson hopes that the support for 16 bit images will result in even smoother tonal transitions in digital negatives.
Someday maybe I'll figure out what the issue is with the 4800 and 9800 printers. I've already varied platen height, ink density, print quality (dpi), suction, orientation of the media (when cut into sheets), and colors used for the negative. For now I don't use these two printers for making digital negatives.
I have not tried to produce digital negatives on other printers besides Epson. I suspect that is in my future.