Formation
Formation refers to the uniformity and distribution of fibers within a sheet of paper. Well-formed sheets have less show-through and solid ink coverage will lay down smoothly. A poorly formed sheet will exhibit a mottled appearance when printed. Formation can be checked by holding the paper up to a light source: A well-formed sheet appears uniform, while a poorly-formed paper has clumps of fibers, giving it a cloudy look.
Opacity
Opacity is the measurement of light passing through a sheet of paper. The more opaque a paper is, the less show-through there will be from printing on the sheet below.
Brightness
Brightness is measured as the percentage of light reflected from the surface of the paper. It is not necessarily related to color or whiteness. A paper with a brightness of 99 is an extremely bright sheet with almost all light being reflected back to the viewer. Bright white papers illuminate transparent printing inks, giving cleaner, crisper color and high-contrast blacks.
Finish/Smoothness
There is a wide range of finishes, or textures, of paper. Even if you want a smooth sheet there is quite a range. The characteristic of smoothness affects ink receptivity and ink hold-out. Smoothness is measured on the Sheffield scale. A higher value typically indicates a rougher sheet—for example, coated paper may have a smoothness of 10-30, vellum offset from 200-250.
Formation refers to the uniformity and distribution of fibers within a sheet of paper. Well-formed sheets have less show-through and solid ink coverage will lay down smoothly. A poorly formed sheet will exhibit a mottled appearance when printed. Formation can be checked by holding the paper up to a light source: A well-formed sheet appears uniform, while a poorly-formed paper has clumps of fibers, giving it a cloudy look.
Opacity
Opacity is the measurement of light passing through a sheet of paper. The more opaque a paper is, the less show-through there will be from printing on the sheet below.
Brightness
Brightness is measured as the percentage of light reflected from the surface of the paper. It is not necessarily related to color or whiteness. A paper with a brightness of 99 is an extremely bright sheet with almost all light being reflected back to the viewer. Bright white papers illuminate transparent printing inks, giving cleaner, crisper color and high-contrast blacks.
Finish/Smoothness
There is a wide range of finishes, or textures, of paper. Even if you want a smooth sheet there is quite a range. The characteristic of smoothness affects ink receptivity and ink hold-out. Smoothness is measured on the Sheffield scale. A higher value typically indicates a rougher sheet—for example, coated paper may have a smoothness of 10-30, vellum offset from 200-250.
The print quality of a paper will be determined by formation, smoothness, brightness, opacity and if applicable, surface coating. Always request samples that demonstrate how a paper prints before specifying it . Your merchant specification rep can provide real-world projects on the paper in addition to mill promotions.
]]>