Good suggestion with the different print heads for different inks; with the HP 2800 this isn't a problem since it has separate heads. My best guess after reading around at Color Workshop:s home page is that they are using ink from
American Inkjet since Color Workshop claims that they're using ink from a US based corporation that have been around for 20 years; some of the sales pitch are similar as well. Then again I could be wrong; but about American Inkjet; anything good or negative that can be said about them?
Never tried them - but that they have lasted so long is a good indication... can't find much on them, but a lot of places seem to use or resell their products.