HP LJ 2100M, LJ 4000TN Paper grades basic sizes and basis weights, Category Specification

Paper specifications (continued)

Category	Specification
Grain	long grain

	Note
	If paper is greater than 135 g/m2 (36 lb)
	use short grain.
Moisture content	4 percent to 6 percent by weight
Smoothness	100 to 250 Sheffield

U.S. paper grades

The U.S. paper grading system has evolved from custom and usage rather than from a technical background, resulting in similar papers having different stated weights. For example, a 24# bond paper is exactly the same weight as a 60# book or a 60# text or a 33# cover. This is because basis weight is defined as the weight of 500 sheets of paper cut to basic size. The basic size for bond, book/text, cover, index, bristol, and tag are all different so the given weights for these paper grades might be different although the physical weight is virtually identical. The following tables will help clarify these differences. Note the difference in basic size for each grade, which affects the weight of

500 sheets of that grade:

U.S. paper grades: basic sizes and basis weights

Paper	Basic size	Basic area	Factor	Equivalent
grade				basis
				weights
				(example)
Bond	17 by 22 in	374.0 sq.in	1.00	24# bond
Text	25 by 38 in	950.0 sq. in	2.54	61# text
Book (coated	25 by 3 in	950.0 sq. in	2.54	61# book
or uncoated)
Cover	20 by 26 in	520.0 sq. in	1.39	33# cover
Bristol	22.5 by 28.5 in	641.25 sq. in	1.71	41# bristol
Index	25.5 by 30.5 in	777.75 sq. in	2.08	50# index

152 Chapter 5 – Media specifications EN