For all those who love producing their own colour prints but struggle with Gloss Differential issues on RC type papers using Epson UltraChrome K3 pigment inks - I have come up with a satisfactory solution for my own purposes. Even though everyone says that it doesn't matter and that you only notice it when viewing on an angle and that it disappears when the print is behind glass - - - those reasonings are small consolation when clients notice it and think that you are stiffing them with inferior prints.
I have always benefited from the "Highlight Point Shift" feature when printing Black and White prints using the "Advanced B&W Photo" setting. What the Highlight Point Shift option does (for those who aren't aware) is lay down a light gray spray of ink onto the whole page so that the white areas that receive no ink and as a result have a different surface appearance to the areas that have received ink - end up with a subtle layer of ink that still allows the appearance of white, but blends in quite well with the rest of the page.
For some time I have considered figuring out a way to benefit from the same gray underlay with my colour prints - but only recently got around to trying it out. What I have done is created a blank NEW page in photoshop and use it to print the sheets of paper using "Advanced B&W Photo" > "Settings" > "Highlight Point Shift". Once I have printed the sheet by laying down the light ink base I then ran the paper through the Epson again printing the colour image (it worked just as well doing it after the colour was printed also). Even using images where there were highlights with little detail, the Gloss Differential problem was barely noticable.
One thing that I realized is that I couldn't just run a blank page through the printer - there has to be some content for the printer to feed the paper through. What I did was add some very small text to the top corner of the page using an ink opacity that was barely visible - - - that either ends up outside of the printable area when printing 8x10's on 8 1/2x11 paper, or as a result of hardly being noticable blends in with the rest of the image on full bleed 8x10 paper.
I have used this method on both Luster and Premium Glossy paper with good success. Yes it takes a little more time running the paper through twice (I generally print several sheets with the gray underlay at one time) - but the results are worth it and I don't have to worry any longer about clients noticing the ink coverage and adding to the mistruct many currently have for digital prints. From what I have noticed in printing with the Epson 2200 and 2400 for the last several years, it seems that people have more of an issue with small prints than larger ones - - - they seem to be so conditioned to what 4x5, 5x7 and 8x10 prints are supposed to look like that the gloss differential sticks out like a sore thumb to them. If you just love the control of making your own prints and are likewise bothered by the Gloss Differential look, you may want to give this a try. Post here if you have tried it and the results you've had - - - I'd be curious.
