Epson inks - Photo Black vs Matt Black

Photo Black on Velvet Fine Art paper

Matt Black on Velvet Fine Art paper
Got a bunch of velvet fine art (VFA) watercolor papers when I bought my Epson 2200 printer off craigslist. Never got around to printing on it since it is supposed to need Matt Black (MK) ink in place of Photo Black (PK). A cartridge swap wastes ink, so I decided to wait till PK is low enough to do a comparison. First print turned out very muddy, but then I figured I printed it on the wrong side. Waste of one nice 13x19 VFA to learn how to figure the printing side (Lick a finger and rub on paper, the tacky side is the print side). The following print on the correct side came out much better, good enough to mat and gift to someone. I did a few more till the PK ink ran out. Time for the Matt magic as all the online articles say. Had to do the usual delete-printer-and-add-again trick on the mac to get the MK ink recognized. Out came the next print. I could not believe how much better it was. The image seemed to jump out of the paper. The illustrated comparison only gives a rough idea about the difference.
Just to check how the MK ink performs with normal glossy paper I did a test 4x6 print. It indeed makes some weird reflections but looking directly at the image makes it look normal enough.