I think it must be a question of printer settings. I use the predessor of the Epson 2200, the 2000P, which has lower resolution than the 2200 and my prints from OHP negatives are very smooth and definitely not gritty or grainy.
Originally Posted by rogein
Make sure that you are using the following settings (assuming a grayscale file).
Media = Glossy Paper (not OHP)
Ink = Color
Mode = Automatic
A dialog box should let you know that fast speed printing is turned off and that you are printing in photo, or maximum, resolution.
Also, use Pictorico. I don't know of any other OHP material that works with the Epson 2200. It is possible that there are others but I have not heard of anyone having success with anything other than Pictorico.
No point in using profiles here, you just need to be consistent.