Brightness is the measure of the amount of blue light reflected off a sheet of paper. Essentially the volume of light.

Whiteness is the measure of the amount of all light reflected off a sheet of paper. Essentially the quality of light.

This article will deal with paper whiteness; what it is, how it is determined, and how it affects print quality.

To read more, see our All About Brightness article.

SUMMARY

WHAT IS WHITENESS?	SHADES	TESTING	PRINT RESULTS
Whiteness is the measurement of how much light from every spectrum (ie: white light) is reflected off the surface of the paper. Whiteness is rated by shade or a percentage.	In lieu of a whiteness percentage a name, called the shade, may be applied to the paper. The three basic shade designations are: True white, Blue white, and Cream white.	Whiteness is determined using the D65 Illumination Whiteness Test. This test determines the amount of natural light reflected off the paper's surface.	The whiteness of a paper will affect how the printed image appears upon it. Bright white papers provide more contrast and a wider gamut.

Because Whiteness is calculating the "white" light reflected off the surface of the paper, it is a more reliable determination of how white the paper appears to the human eye than the Brightness rating. Similarly, whiteness will affect the color of a printed image.

Since a specific type or mixture of light is used to test it, however, a paper considered very white could still appear otherwise under different lighting.

Whiteness is measured on a scale of 1-100%. It is generally quite simple to pick out the whiter/whitest paper, at least under the test lighting conditions, while Brightness is generally a harder quality to pinpoint visually.

Any glossy coating must be taken into consideration when visually assessing whiteness, as well, as the paper's appearance will be altered by this added, reflective surface.

Unfortunately, shade names are not standardized, so you should never assume two different papers are the same just because they share a shade name.

• Blue White is often used, as it appears whiter to the eye. Blue white papers absorb yellows and warmer wavelengths and reflect blue or cooler wavelengths.

• Cream White papers have a yellowish tint, due to the fact they absorb blues and cooler colors, and reflect yellows and warmer colors. Cream white may also be called "warm white".

• True White refers to papers that reflect all wavelengths equally. Therefore, under the correct lighting conditions they will appear absolutely white. True white is also known as "balanced white".

The test is conducted using a light source of outdoor daylight, and the resulting rating is called the CIE Whiteness Standard, as it is set by the International Commission on Illumination (CIE).

Specifically this D65 test corresponds to what is approximately midday sun in Western and Northern Europe. Despite this focus on natural light, light simulators are used for the test in lieu of real sunlight. This simulation is the CIE D65 daylight illuminant,

The test also includes a standardized way of adjusting the data based on the UV content when artificial brighteners have been used in the paper.

FINE ART PAPERS	WHITENESS
Hahnemühle Photo Rag	92.5 %
Hahnemühle German Etching	91.5 %
Hahnemühle William Turner	88.5 %
Hahnemühle FineArt Baryta	103 %
Hahnemühle FineArt Pearl	105 %
Epson UltraSmooth Hot Press	Natural White
Epson Enhanced Matte	Bright White

An image printed on a glossy paper will, naturally, be more reflective than the same image printed on matte, textured papers. This is because the light is reflected readily off the surface of the coated paper, and is diffused (scattered) across the surface of the uncoated paper.

Papers with a high whiteness rating will reflect more light, therefore allowing for more contrast in the printed image. High brightness and whiteness also tends to correlate with wide color gamut. These papers are useful for digital art and brightly colored art reproductions, because the eye is accustomed to seeing the image with a great deal of contrast and saturation (on the computer screen, or on a white-primed canvas).

Papers that are less white will have less contrast and a lower color gamut. This may be a desirable choice for reproductions of sketches, charcoal, and other, less color-centric artwork we are accustomed to viewing in this way.

Most photographic papers are very white and bright. If, however, an antique or less saturated appearance is desired, a less white fine art paper is an alternative.

Though different papers will always prouce slightly different results, a good print technician will know how to alter the digital image to suitably compensate in most instances.

If you have questions about any of our fine art paper prints, or any of our other services or products, don't hesitate to contact us. Our knowledgeable staff is always happy to assist with answers, advice, or suggestions.

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