🚀 go-pugleaf

For Advanced Black and White to work as expected, and it does work extremely well, you need to send it non color managed Adobe RGB. The one thing that ABW actually is expecting, is that the file is in a Gamma 2.2 "color" space.

You can send the printer a file that is a black and white version of Adobe RGB or a Gamma 2.2 Grayscale. It doesn't matter. The file gets mapped to the three black inks and will make a very nice black and white. If you use the Tint dialog in ABW the driver will add small amount of colored ink to create the desired tint but the image will still primarily be made of the black inks.

Another minor note. The d-max of the blackest printable black is a bit lower when printing through ABW mode as compared to a full color image. No one has ever said why this is, but it is the case nevertheless. It's something you can measure with a densitometer or spectrophotometer and something you can see just observing the prints.