The R1900 has a single shade of black and gloss optimiser (like the 1800)
Brian,
The R1800/1900 has a Photo Black and a Matte black cartridge in it.
I made a few prints on good Epson Matte paper, but never got the WOW factor that I get with Luster which is a sort of semi gloss.
Years ago, I had an Epson 1280 which made glorious prints on Premium Glossy, Premium Luster, and for matte paper, I used Epson Colorlife.
The R1800 does not work with Colorlife paper and the pigment inks, so that was discarded and I am left with Prem Luster or Prem. Glossy.
I have some Ilford paper too, but when I am making serious prints for presentation, I go to my stock of Epson paper.
Fred