A perceptual attribute that rises with lightness and with a slight blue cast, and drops quickly with any yellow cast. Because the eye judges whiteness over the full spectrum, instruments express it through formulas built on colorimetric values, the most common being CIE whiteness. Whiteness and brightness move together on undyed sheets but split apart once shading dyes or optical brighteners are added.
Brightness is flat but whiteness dropped six units since we cut the violet dye, and the printer spotted it straight away.
Related terms
CIE whiteness
Formula-based whiteness index computed from luminance factor Y and chromaticity, under D65 or C illumination.
Brightness
The blue-light reflectance of pulp or paper, read at an effective wavelength of 457 nm and reported as a percentage.
Tint
Companion value to CIE whiteness that tells whether a white leans toward green or toward red.
Shading dye
Small dose of blue or violet dye used to cancel the yellow cast of a white sheet and steer its tint.
Blue-white
Trade description of a white shaded and brightened toward blue so it reads cool and very white.