The Paper Trifecta: Whiteness, Brightness and Shade

I was stunned. Stunned that someone I would consider an industry expert obviously did not know their stuff. With an easy swagger he interchangeably used the terms "whiteness" and "brightness" and "shade." Well, my mother taught me "If you cannot say something nice..." So I will not tell you to whom I am referring, nor the exact wording he used—Google might find him, you see.

Anyway, here I am to set the record straight.

Brightness, whiteness and shade are three very independent paper properties, even though they are often mistakenly used interchangeably. A paper has all three; one does not exist without the other.

In North America, we are used to seeing a value for brightness applied to everything from copy paper to commercial printing sheets. Yet different countries have established norms based on their own preferences. Europe and the rest of the world have put more emphasis on whiteness rather than brightness. (It’s the metric-imperial measurement divide all over again.)

But what do these three terms actually mean?

Brightness is often defined as the reflection of light off a paper’s surface. Unfortunately, this is only partially true. What is actually measured is the reflection of light across a wavelength of blue light.

TAPPI’s GE standard, mostly used in North America, is based on a scale of 0-100. The higher the brightness value, the more light is reflected by the sheet of paper. Therefore, a paper with a 98 brightness reflects more light than one with a 92 brightness.

Globally, brightness is no longer a primary measure for paper. It has been replaced by CIE whiteness, which is more relevant, as it measures the paper as your eye perceives it.

CIE Whiteness: Developed by the French International Commission on Illumination (CIE), this is the most commonly used whiteness index.

It refers to measurements made under D65 illumination, which is a standard representation of outdoor daylight. For a perfect reflecting, nonfluorescent white material, the CIE Whiteness value would be 100.

Shade refers to the actual white color of a paper, with general differentiations of blue-white, balanced white and warm white. Thanks to optical brighteners, most of the white papers available today have a blue-white shade. They make the paper appear brighter and therefore whiter.

Now that wasn’t so hard, was it? But I am sure this is not the only terminology that causes problems. What terms do you hear being used interchangeably?