Printer recommendation

[mercurius]

almost all colors are a mix of CMY inks, and gray is just one out of the millions overall, and gray is always mixed. That's not too bad, you don't see the individual colors but the composite, the problem with such grays becomes visible when gray tones are viewed under different light conditions - daylight or incandescent light or neon tubes etc - and specifically gray tones then appear to get a color cast . And it is this effect, and some more related to that , which are better under control with the use of a gray ink, all larger scale photo printers - Canon or Epson use one or two gray toned inks for this reason. This is valid for all color prints - monochrome prints are just a special case, and they get better as well with an additional gray ink-

OK, IsF, thanks for this very helpful explanation