ply
1. One of the separate layers of paper or board
comprising the sheet formed on a multi-cylinder
papermaking machine. Each cylinder adds one layer
(web), which is then pressed to another, both or
all of which adhere firmly upon drying. The
thickness of the resultant board is generally
expressed in the number of layers of which it is
composed. The equivalent ply ratings in
thousandths of an inch are given below:
Ply Inches
2 0.012
3 0.015
4 0.018
5 0.021
6 0.024
8 0.030
10 0.036
12 0.042
14 0.048
16 0.056
2. One of the sheets laminated to build up a
pasted board of given thickness. (17 , 278 )