The tones can be controlled in a number of ways either with print workflow controls (driver sliders, curves, etc.) or by simply changing one or more of the re-usable carts in, for example, the Epson C86.
Depending on the printer and workflow, these predominantly carbon-pigment inksets can be printed by most computer applications, but avid photographers will want Photoshop.
The process of making archival, digital B&W prints is now easy and affordable.
"Carbon on cotton" is now my medium of choice for the most archival B&W images. This combination of carbon image-forming substance and acid-free cotton substrate should be about as archival as any medium ever has been. Our civilization will be lucky to last as long.
For an index of carbon pigment printing information, including details of the inksets and settings, click here.
To purchase variable-tone inksets, see the MIS website.
For an excellent Internet forum devoted to black and white digital printing, visit the Digital B&W Print Forum.
If you have any questions about the inksets I use or images on my website, feel free to contact me.