Digital BW, The Print

This afternoon, I took a close look at a 21-step grayscale wedge printed with ImagePrint and one printed using the Epson RIP on a 2200 printer. Both prints exhibit no metamerism although the Epson RIP print looks warmer in tone than the neutral IP print. Both were printed on EEM using the Matte Black ink at 1440 quality. 

Here is what I observed: 

The Epson RIP (using Sandy Cornelius' workflow) uses only the Light Black ink for patches from 1 to 10%. At 15%, it starts adding Light Cyan and Light Magenta ink. At 85%, it adds Black ink. I was not able to see any Yellow ink used at all. 

ImagePrint uses Light Black, Light Cyan, and Light Magenta starting at the 1% patch. At the 75% patch, it adds Black ink. I also did not see any Yellow ink used by IP. 

Furthermore, I noticed what appears to be a registration error between the Black ink and Light colored inks in the IP print. It is most noticable in black text or wherever there is a black line on the print and shows up as a Light Cyan outline below the black with Light Magenta or Light Black as well. I'm inclined to believe this is a bug in the IP driver and not a problem with my particular printer since I don't see the problem using the Epson RIP. I am willing to test that theory though if someone would be willing to send me a step wedge printed on their 2200 using IP. 

It is difficult to see this registration error with the eye on EEM paper, but it is clearly visible to the naked eye in a step-wedge print I made on Professional Glossy Paper using the Photo Black ink in the 3.6lp/mm and 7.2lp/mm horizontal targets. 

I am trying to find a camera adaptor for the "phototube" of this microscope so I can take some pictures and post them. And I will email my observation to Colorbyte and see if they are aware of any such "bug" that could cause this. 

--Tom