Dmax – Maximum Density

           Original | Reduced Dmax
Reduced Dmax on the right

Dmax = -log10(minimum print reflectivity) is a measure of the deepest black tone a display or printer/ink/paper combination can reproduce. It is an extremely important quality factor. Images with poor Dmax look pale and weak. Dmax = 1.7 is a good value for matte prints; 2.0 is a good value for glossy, semigloss, and luster prints. There have been reports that Epson Ultrachrome K3 printers have Dmax as high as 2.3 with Premium Luster paper. That would be outstanding.

Dmax is measured by Print Test, along with the Printer’s tonal response curve and the color factors described below. Print test requires a decent flatbed scanner, and for best accuracy, a Step chart.

Dmax is affected by the printer, paper, and ink. The response curve is also affected by the ICC profile. Print Test can help with the selection of supplies and diagnosis of printing problems.