Whiteness formulas: a selection.

Experience in assessing whiteness and industrial requirements is considered in the selection of whiteness formulas. The problems set by the photometry of fluorescent samples and the calorimetric prerequisites delimit the choice. A standard whiteness formula of neutral hue preference is proposed. Two supplementary whiteness formulas of green and red hue preference, respectively, are added. The feasibility of a complete characterization of white samples by whiteness, tint, and luminance factor is discussed.