Printing Knowledge
Printing Knowledge

Paper Weight - Let’s End the Confusion

In an effort to help eliminate the "Paper Weight" confusion problem,
we have compiled the comprehensive table listed below.
Now you can compare various types of paper and their "Equivalent Weights."

Definitions:

Basis Weight

The basis weight of a paper is the designated fixed weight of 500 sheets, measured in pounds, in that paper's basic sheet size. It is important to note that the "basic sheet size" is not the same for all types of paper.

Caliper

Caliper refers to the thickness of a sheet of paper expressed in thousandth of an inch. This measurement is taken with a micro meter. Normally, paper caliper should not have more than a + or - 5% variance within a sheet. Generally, the relation between caliper and basis weight .... the greater the caliper (the thicker the paper), the greater the paper weight.

Equivalent Weight

While different paper types have different basic sizes, papers can still be compared by using equivalent weight.

Basis Weight ("Category") Table

Type Paper Basic Size - 500 Sheets
Bond: Ledger, Mimeo, Duplicator, Rag Paper 17" × 22"
Offset: Book, Text, Coated Paper 25" × 38"
Cover 20" ×  26"
Tag Stock 24" × 36"
Index 25-1/2" x 30-1/2"

The Values in the table below are intended to serve as a guide only. They should not be used as specifications because there are variances within the same basis weight due to other characteristics of the papers. Similar weight papers may vary between different paper manufacturers.

Bond Ledger Offset Text Cover Tag Index Points *Caliper(inches) millimeters Metric(grams/sq meter)
16 40 22 37 33 3.2 .0032 0.081 60.2 gsm
18 45 24 41 37 3.6 .0036 0.092 67.72 gsm
20 50 28 46 42 3.8 .0038 0.097 75.2 gsm
24 60 33 56 50 4.8 .0048 0.12 90.3 gsm
28 70 39 64 58 5.8 .0058 0.147 105.35 gsm
29 73 40 62 60 6 .0060 0.152 109.11 gsm
31 81 45 73 66 6.1 .0061 0.155 116.63 gsm
35 90 48 80 74 6.2 .0062 0.157 131.68 gsm
36 90 50 82 75 6.8 .0068 0.173 135.45 gsm
39 100 54 90 81 7.2 .0072 0.183 146.73 gsm
40 100 56 93 83 7.3 .0073 0.185 150.5 gsm
43 110 60 100 90 7.4 .0074 0.188 161.78 gsm
44 110 61 102 92 7.6 .0076 0.193 165.55 gsm
47 120 65 108 97 8 .0078 0.198 176.83 gsm
53 135 74 122 110 9 .0085 0.216 199.41 gsm
54 137 75 125 113 9 .009 0.229 203.17 gsm
58 146 80 134 120 9.5 .0092 0.234 218.22 gsm
65 165 90 150 135 10 .0095 0.241 244.56 gsm
67 170 93 156 140 10.5 .010 0.25 252.08 gsm
72 183 100 166 150 11 .011 0.289 270.9 gsm
76 192 105 175 158 13 .013 0.33 285.95 gsm
82 208 114 189 170 14 .014 0.356 308.52 gsm
87 220 120 200 180 15 .015 0.38 312 gsm
105 267 146 244 220 18 .0175 0.445 385.06 gsm

• The darker colored boxes above represent the "most common paper weights" for that category.
• Normal paper manufacturing tolerance within a paper production run is + or - 5% to 7% caliper
• This Table was compiled by Micro Format, Inc.

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