Bookbinding and the Conservation of Books
A Dictionary of Descriptive Terminology

groundwood printing papers

As the name suggests, they contain a proportion of mechanical wood pulp, but it is a pulp carefully prepared, and therefore clean and bright. The use of mechanical pulp for this type of printing paper improves important characteristics of the paper, such as retention of loadings, high bulk, greater opacity for the basis weight, improved softness, and a smoother finish. They are, however, inferior to the chemical wood pulp papers in both permanency and brightness. They are made in a number of furnishes ranging from approximately 75% mechanical pulp to about 20 to 25% mechanical, the balance being chemical pulp. They are sized, finished, colored, loaded, and coated in various ways to make them suitable for virtually any printing process. Their life expectancy, however, even under good storage conditions, is probably under 25 years. (17 , 72 , 324 )