The dependence of paper whiteness on its surface roughness is studied by numerical modeling of measuring apparatus and specimen scattering properties. The dependencies compared for various specimen illumination component with and without allowing for the specular component of scattered light are compared. The whiteness is calculated by ISO/DIS 11475. It is found that the whiteness of the object under study depends on both surface roughness and the illumination scheme selection, whereas the chromaticity coordinates depend on neither of them. (C) 2000 John Wiley & Sons. Inc.