Some dye-sub systems have offered dedicated black-and-white media—for example, certain Canon Selphy ES models had BWO (black/white/overcoat) cassettes—but this does not appear to be common across dye-sub lines.

With standard CMYO dye-sub media, black-and-white output is possible, but neutral grayscale is generally not considered a strength compared with modern photo inkjets. Community references point to dye-sub falling short of inkjet for black-and-white/grayscale rendering, where neutrality and tonal control matter most.

A key reason is that many modern photo inkjets are specifically designed for monochrome printing, often using multiple grayscale inks such as black, gray, and light gray. That helps produce smoother tonal transitions and better neutrality, especially on papers made for fine-art black-and-white work.

Dye-sub printers do have continuous-tone output, so adding extra gray panels is not necessarily required in the same way additional inks help inkjets. But in practice, if your priority is the best black-and-white tonal range and neutrality, a modern grayscale-capable inkjet is usually the better choice.

So: dedicated B&W dye-sub media exists in some cases, but for top monochrome quality, inkjet is generally preferred.