Welcome to our #OKalphabetseries where we will be visiting paper and printing terms daily. Come back each day as we weave our way through the alphabet and share our 110 years of knowledge with you.

C is for CALIPER
Caliper is the thickness of a single sheet of paper, measured in thousandths of an inch, mils or points. Caliper is measured using a micrometer, a device which measures minute thicknesses of paper by applying a static load for a set period of time. Consistency of caliper throughout a manufactured roll of paper is important. Increases or decreases in caliper can affect the extent to which the printing plate or blanket contacts the paper and affects printability and runnability. The thickness of a paper itself varies according to the basis weight desired or end-use considerations. Caliper can be reduced or increased at a variety of stages in the papermaking process. The  amount of pulp, dyes and sizing deposited on the wet end of the paper machine can be reduced or increased. The process of calendaring (rendering surface smoothness) can reduce the thickness of the paper.

Welcome to our #OKalphabetseries where we will be visiting paper and printing terms daily. Come back each day as we weave our way through the alphabet and share our 110 years of knowledge with you.

B is for BASIS WEIGHT
Paper is commonly identified using basis weight - 24 Writing or a 80 Text, 100 Cover. Weighing 500 sheets (a ream) of any grade of paper in its standard basic size will determine its basis weight. To put it simply, 500 sheets of 17 x 22 (the basic size for a writing grade paper) of 24 lb. writing paper will weigh 24 pounds. Each type of paper has a standard basic size determined from over a century of manufacturing these different type of sheets. As printing presses and machinery changes, these basic paper sizes do not.

• Text, Book and Offset paper’s standard basic size is 25 x 38
• Writing, Bond and Ledger paper’s standard basic size is 17 x 22
• Cover paper’s standard basic size is 26 x 20
• Newsprint, Tag, Tissue and Board’s standard basic size is 24 x 36

The basis weight of a paper strongly influences the strength properties and paper traits such as thickness, opacity and runnability.