Paper - The Graphic Design: Reference and Specification - page 68

b a s i s w e i g h t / c a l i p e r e q u i v a l e n t s
The following chart gives an approximate caliper thickness for the different basis
weights of some common papers. Because a paper's finish also affects its thickness
or bulk, calipers are also given for common finishes.

Basis Weight Coated Smooth Vellum Textured

Bond/Writing

13# 0.0021 0.0025 0.0027

16# 0.0026 0.0031 0.0033

20# 0.0032 0.0039 0.0042

24# 0.0038 0.0047 0.0050

Index

90# 0.0080 0.0084

110# 0.0096 0.0104

140# 0.0132 0.0140

170# 0.0144 0.0160

Book/Text

40# 0.0025 0.0031 0.0034

50# 0.0023 0.0031 0.0038 0.0041

60# 0.0028 0.0038 0.0046 0.0050

70# 0.0034 0.0044 0.0054 0.0058

80# 0.0040 0.0050 0.0059 0.0065

90# 0.0046 0.0057 0.0065 0.0074

100# 0.0052 0.0063 0.0071 0.0082

120# 0.0060 0.0076 0.0082 0.0100

Cover

50# 0.0058 0.0070 0.0075

80# 0.0072 0.0093 0.0113 0.0120

100# 0.0092 0.0116 0.0140 0.0150

ppi fOrmulA
Determining pages per inch can be important for determining the thickness of a finished
publication. To calculate the number of pages per inch, calculate the caliper (points)
of eight pages (four sheets) then divide the number of points into eight. In the following
example, four sheets of a hypothetical paper measures 0.016 inch in thickness.

Example: 8.000 ÷ 0.016 = 500 ppi