Paper basis weight --- conversion of metric and imperial system

Quantitative is also called gram weight. In Hong Kong and Taiwan, it is called the basic weight, commonly used metric gsm said that this is an international symbol. However, the U.S. and U.K. use the English system, which measures the weight of paper in pounds (Lb), indicates the thickness of paper and paperboard in points, and serves as a ruler for dividing paper and paperboard, specifying 12 points or more as cardboard; 12 The following points are paper. 1 point is one-thousandth of an inch, if converted to metric: 1 point = 0.0254mm; 12 points ≈ 0.3mm. It can be seen that 0.3mm thickness is the dividing line between paper and cardboard. There are two other representations (used in the US) for cardboard rations: pounds/1000 ft 2 (LBS/1000 ft 2) and pounds/3000 ft 2 (LBS/1000 ft 2), the former for cardboard and the latter for thin cardboard. If you convert from English to metric, multiply by a factor of: g/m2 = (pounds/1000 feet2) x 4.888; g/m2 = (pounds/3000 feet2) x 1.627.