I appreciate the responses. Here's the deal. I have tried some different papers with my Epson printers (3800 & P6000) - the Moab papers, the Canson Infinity papers, Red River papers, Epson papers, and a few others. Among the things I like about the Moab Juniper and Entrada is how it feels in the hand. For me, there is a richness in the feel of those papers. Both are pretty heavy and both are cotton rag. "Nuff about those.
The Canon PRO-100 came in a package deal when I bought my 5D3. On the theory that two printers are better than one, I figured three would be better than two. So I set it up and have used it sporatically to basically check out photos I want to print before go to the Moab papers and the Epson printers. The paper I have ended up using most often is the Pro Luster.
Just recently I picked up a pack of Premium Pro Matte (8.5 x 11 which is what I use for my 6 x 9 test prints). I had an issue arise that I remembered occurring when I tried to run some other (Moab) papers through the PRO-100. The issue I have is with the Fine Art Papers which require the "Art Paper Margin 30" paper setting. Premium Pro Matte is one such paper. With a fine art paper and the "Art Paper Margin 30" setting for Letter sized paper, the largest print surface will be just 5.76 x 8.64. I can even get to 6 x 9 and forget trying to do a 8 x 10.
I spoke to someone from Canon yesterday who was very helpful in explaining why that is the case and why you can't override it. It has to do with the rollers in the PRO-100 and how the paper has to come in contact with the second set of rollers which required 30mm of paper leading and and out. Ergo the reason for the mandatory 1.18" left and right margin.
The only alternative is to use the Matte Paper setting under photo paper and regular Letter for paper size. Then I can make 6 x 9s or whatever. But the rep also warned that doing this may not always work.
I made two prints of the same photo using both settings. The "hack" works but when looking at the two prints side-by-side, I can see a difference. The print using the "hack" settings appear more faded and flat that the one using the Fine Art Paper setting.
What does all this mean? It means that I am finding the Canon printer (specifically the PRO-100) more difficult to work with than the Epsons and, more importantly maybe, more difficult to deal with than I am willing to deal with. I don't know if this issue is the same with other printers in the PIXMA PRO line.
Sorry for the ramble.
Ed