September 2007 e-gram
Paper: Making The Grade
You may not have thought much about grades since you left school and your quest for that elusive "A." But it pays to think about grades when you are selecting paper for a project. The grade of paper you select affects how the ink appears in your printed piece. Paper grade actually is a general term that depends on context. It may refer to the category, class, rating, or finish of the paper.
People most often use the term grade to talk about the category of the paper. Generally, paper is divided into five grades. Bond paper is used for projects such as letterhead and forms, which may be run through office equipment. Offset or uncoated book papers are used in offset printing when you need a smooth, uncoated paper for projects such as brochures or annual reports. Coated book is the glossy version of uncoated book paper. Text papers have more texture than book papers, and come in different finishes such as laid, linen, vellum or felt. Cover papers are used for projects that require a heavier stock such as postcards or business cards.
Other paper distinctions are based on characteristics such as brightness, opacity, and ink holdout. All white papers are not equally white, and the brightness of a paper is rated by how much light the paper reflects on a scale from 1 to 100. A paper with a brightness of 80 does not seem as white as one in the 90s.
The term opacity is used to describe how well the paper stops light (and printing on the other side) from showing through the paper. Ink holdout describes how well the paper prevents ink from absorbing into it. Coated papers are less absorbent than uncoated ones so they have a greater ink holdout.
Papers are also distinguished by their basis weight, which depends on the grade (category) of paper. The basis weight is the weight of 500 sheets of paper cut to the "basic" size. That size is not the same for each paper, so similar sheets of different papers may have different basis weights. Although all the paper classifications are helpful, there is no substitute for looking at and feeling samples of the papers you are considering.