Understanding Paper Brightness

Brightness and whiteness are not the same

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How white is white? Paper classifications are based on levels of whiteness and brightness, but brightness and whiteness are not the same. Both affect the images printed on the paper, especially the vibrancy of colors.

Measuring Paper Brightness

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Brightness measures the reflectance of a specific wavelength of blue light — 457 nanometers. The brightness of a piece of paper is typically expressed on a scale of 1 to 100, with 100 being the brightest. Paper rated in the 90s reflects more light than paper rated in the 80s, which makes it appear brighter.

Manufacturers often use terms such as "bright white" and "ultrabright" instead of numbers. These labels can be deceiving: They're not truly indicative of the brightness or whiteness of the paper.

The multipurpose bond paper used in copy machines and desktop printers generally has a paper brightness in the 80s; photo papers are typically in the mid to high 90s.

Measuring Paper Whiteness

Whereas brightness measures the reflection of a specific wavelength of light, whiteness measures the reflection of all wavelengths of light in the visible spectrum. Whiteness also uses a 1 to 100 scale — the higher the number, the whiter the paper.

Individually, white papers may all appear quite white; however, when placed side by side, white papers show a range of colors from bright, cool white to a softer, warm white. For ordinary usage, the best measure of paper whiteness is your eye and the appearance of your image on the paper.

Brightness, Whiteness, and Finish Affect Image Color

The brighter and whiter the paper, the brighter, lighter, and more vibrantly colored the images that are printed on it appear. Photos, for example, appear brighter and colors clearer on inkjet photo papers with high paper brightness ratings. However, some light colors can appear washed out on the whitest papers. Colors on less bright papers are noticeably darker.

The finish of a paper — the degree of gloss — matters, too. Images on matte paper with a high brightness rating are muted compared to those on high-gloss or glazed paper.

Your Eye vs. Paper Brightness Rating

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With so many variables affecting image quality, the true test is how your images print on a given piece of paper with your particular printer. Before making a sizable investment in a specific type of paper, print some images on in-store printers like your own, ask for paper samples to try at home, or ask your commercial printer or paper supplier for samples printed on paper you are considering.