Chameleon Printing & Copying - Paper Weights, Grades & Sizes

PAPER WEIGHTS, SIZES AND GRADES
When you realize that an 8½" x 11" sheet of 70 lb. offset text weighs less than an 8½" x 11" sheet of 65 lb. cover, it’s hard to believe that paper weights actually are determined by weighing the paper! The problem in understanding this concept, however, is that each grade of paper has one standard size (called the parent or basis size) that is used to determine its weight. The “weight” is figured by weighing one ream (500 sheets) of paper in a particular paper’s standard or “parent” size.

For instance, the parent size of bond paper is 17" x 22". A ream of 17" x 22" 20 lb. Bond weighs, oddly enough, 20 pounds! A ream of 17" x 22" 24 lb. Bond weighs 24 pounds. It’s that simple. The hard part comes in knowing the parent size of the different grades of paper. Originally, in the printing industry, the parent size was determined on a convenient multiple of the end use of the product. For example, writing grades (bond paper) are traditionally used to produce 8½" x 11" letterhead which yields four sheets out of the parent size of 17" x 22" without waste for this paper grade.

Other grades have different parent sizes such as offset and texts which have a parent size of 25" x 38" or cover stock in which 20" x 26" is the parent size. Sometimes your printer is able to substitute comparable weights for you between paper grades. As an example, 24 lb. bond is roughly the equivalent of 60 lb. offset. That’s because 500 sheets of 17" x 22" bond weigh almost the same as 500 sheets of 25" x 38" offset when cut to the same (end use) size for printing or copying. Unfortunately, the conversion is made more difficult because most full size offset and text is stocked at paper merchants in the 23" x 35" size instead of the 25" x 38" parent size, but that’s another story. It’s also another reason why you should depend on Chameleon Printing to help you with all your selection decisions . . . we can help take the guesswork out of selecting inks, paper, printing techniques, envelopes, you name it, we’re here to help!

The handy table displayed below will give you comparable paper weights across grades. Obviously, not all grades are available in all weights so standard available weights for each grade are displayed in red bold type. You’ll note, as an example, that 65 lb. cover falls right between 90 lb. and 110 lb. index. In another words, if you wanted to substitute an index type sheet for a 65 lb. cover weight, you would have to either go a little heavier or a little lighter. Below the table, we have given you an explanation of the various standard paper grades and their properties.

APPROXIMATE EQUIVALENT PAPER WEIGHTS

Bond
Offset
Cover
Index
Bristol
Tag

17" x 22"
25" x 38"
20" x 26"
25½" x 30½"
22½" x 28½"
24" x 36"

12
30
16
25
20
27

13
33
18
27
22
30

16
40
22
33
27
37

18
45
25
37
30
41

20
50
27
41
34
45

24
60
33
49
40
55

28-Ledger
70
38
57
47
64

31
80
44
65
54
73

32-Ledger
81
45
67
55
74

34
83
47
70
57
76

35
90
49
74
60
82

36-Ledger
91
50
75
62
83

39
100
55
81
67
91

40-Ledger
102
56
83
69
93

43
110
60
90
74
100

47
120
65
98
80
109

53
135
74
110
91
122

54
137
75
113
93
125

58
146
80
120
100
134

65
164
90
135
111
150

67
170
93
140
115
156

70
176
97
146
120
162

72
183
100
150
124
166

76
192
105
158
130
175

82
207
114
170
140
189

87
220
120
180
148
200

93
237
130
194
160
216

109
275
151
225
186
250

BOLD NUMBERS IN RED INDICATE STANDARD PAPER WEIGHT FOR THAT GRADE

PAPER GRADES AND PARENT (BASIS) SIZES
Bond or Writing Grades 17" x 22"
This grade of paper is most commonly used to produce stationery (letters) and business forms. It is also used for copying and duplicating on office equipment such as laser printers and copy machines. Most end-use products are produced in the 8½" x 11" size. The properties of this paper allow for easy application of ink from a pen or typewriter as well as standard offset and letterpress methods. Writing grades used for fancy stationery often contain a percentage of cotton fiber (to increase durability) as well as wood pulp in their composition. They may also carry a distintive “watermark” in the sheet that is pressed into the paper while it is still wet during the manufacturing process. Ledger stocks are another form of writing grade, which is no longer commonly used, but it has properties added that make erasing and altering any writing on the sheet difficult.

Book, Offset, Text or Coated Grades 25" x 38"
While the basis size for all of these paper grades is the same, they each possess different qualities for end use which is explained below:

OFFSET PAPERS are named for their properties which allow them to be used effectively in offset printing. Those properties include sizing (to remain dimensionally stable in multi-color printing) and pick-resistance so that the paper does not adhere to the press blanket during the printing process. Offset stock can be specified for a variety of end-use products.

TEXT GRADES are usually available in a wide variety of colors and finishes. They are, like offset paper, treated with a sizing agent to enhance multi-color offset printing. Text papers are generally used for fancy booklets, announcements and brochures. They have also recently come into popular use for some stationery, although not typically available in less than a 70 lb. weight or the equivalent of a 28 lb. writing grade. (Most letterhead and stationery is usually no heavier than 20 or 24 lb.)

COATED PAPERS consist of a base stock to which a smooth (usually clay) coating has been applied. The coating may be dull (matte), glossy (cast coated) or somewhere in between. Coated stock is generally only available in white and is used for high quality printing, particularly for process color work or the reproduction of photographs.

Cover Grades 20" x 26"
So called for their end use as covers on booklets, catalogs, pamphlets and presentation folders, cover stocks are available in both coated and uncoated varieties. They also come in a wide range of colors and finishes including smooth, laid, linen, felt, flannel and riblaid. They possess qualities which increase dimensional stability, durability and properties to enhance finishing operations such as folding, scoring, die-cutting and embossing. Some cover stocks (such as 160 lb.) are manufactured by pasting two sheets (of 80 lb.) together to form one sheet. Because of this technique, it is possible to obtain cover stock which is a different color on each side of the sheet.

Index Grades 22½" x 35"
Index stock is generally very smooth and has very good characteristics for ink receptivity. Considered one of the "board" stocks, it has a stiffness suitable for posters, tickets and other cards used in business and filing applications. Cannot be easily folded without some form of scoring to prevent cracking or uneven folds.

Bristol Grades 22½" x 28½"
Another of the board grades that is often used when the end product will require folding, embossing or foiling. The softer texture of this sheet allows for some “stretch” without cracking when employing these finishing operations. Generally available as vellum bristol and used as a less expensive alternative to index or tag.

Tag Grades 24" x 36"
This stock is generally used for the manufacture of tags and is made primarily from mechanical pulp or waste stock. Coloring for tag stock is often applied by tinting after the paper is made instead of using a dye in the pulp. That's why tag may sometimes be colored on one side only. Tag grades have a high degree of tensile strength and resistance to water and tearing.

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