Hello, This term is already in the dictionary and should be understood as paperboard (thick cardboard material). There is definitely an error as cardboard is thick paperboard. Cardboard is thicker, more rigid than paperboard. Wikipedia describes paperboard as thick paper with a thickness of 0.25mm or higher and a weight of 224 g/sqm. A specialist dictionary states "A heavy weight, thick, rigid and single or multi-layer sheet. What differentiates paperboard from paper is the weight of the sheet. If paperboard is very heavy it is called Board. Paper heavier than 150 gram per meter square are normally called Paperboard. Cardboard is defined as follows: A thin, stiff paperboard made of pressed paper pulp or sheets of paper pasted together. Used for playing cards, greeting cards, etc. As the first character is pronounced ka3, I would guess that it actually means cardboard. I have already in my personal glossary 纸板 for cardboard. I suppose this is incorrect then? Please note that both cardboard and paperboard are different from corrugated board which has a wavy layer 瓦楞纸 and is used for boxes to package goods. In contrast, cardboard is used for small items such as as cosmetics or medicine or even single bottles. If I am using incorrect Chinese terms, please let me know. Xie4 xie4.