Corrugated Board
It is also called a corrugated paper or paper-skin corrugated pit-shaped paper core with flat paperboard adhered to one or both sides of the sandwich paperboard.
There are single-sided, single-layer (double-sided), double-layer and three-layer corrugated cardboard.

In Guangdong, K, A, B represent cow cardboard, imitation cow cardboard

K=200~250g/m2

A=150~175g

B=120~130g

C represents 127 grams of liner paper

T stands for 160~180g liner paper

W paper represents white paper, cow background white and white noodle cow card