What is the material classification of the carton?

Material classification of paperboard:

Cardboard materials are classified by weight per unit area, mainly including the following types of paperboard materials:

K paper: 250g/m2;

Paper A: 175g/m2;

Paper B: 125g/m2;

7 Paper: 200g/m2;

8 Paper: 260g/m2;

C paper: 127g/m2;

Core paper: basically 100g/m2; Large machine 105-110g/m2;

Reinforced core paper:+paper 115g/m2;

The commonly used cartons have three or five layers, and the seven layers are less used. Each layer is divided into inner paper, corrugated paper, core paper, and face paper. The inner and face paper includes tea board paper, kraft paper, and core paper uses corrugated paper. The color and feel of various types of paper are different, and the paper (color and feel) produced by different manufacturers are also different.