Dmax
The maximum density a print can achieve, measuring how dark its blacks are.
Formula / rule
Dmax = log₁₀(1 / reflectance)
Measured in
density units
In depth
Dmax sets the print's contrast ceiling, since the whitest tone is fixed by the paper. A glossy baryta may reach 2.3 to 2.5, a matte rag around 1.5 to 1.7 — a difference the eye reads immediately as depth. It is a property of the paper, ink and profile together, not of the image.
Examples in practice
The same file printed on baryta and on matte rag differs by nearly a full density unit in its deepest shadow.