Whiteness
The measure of the amount of light reflected from a sheet of paper. How white a paper is depends on how evenly it reflects all colors in the visible spectrum. If it reflects more blue than red and yellow, it will have a cool, blue tinge to it, making it appear brighter than white. A cool paper will appear brighter than a similar paper with a warm tinge. A cool or warm tinge doesn't affect paper quality, but it does create optical impressions. For example, in color printing with blues and blacks predominating, a cool white sheet tends to brighten the colors. But color printing with reds, oranges, and yellows predominating, a neutral or warm white sheet tends to make the colors appear clearer and stronger. See also brightness.