Hey, I’ve done it before! Taishan plaster. After you remove the edge sealing tape, buckle and pull hard on the edge. If the protective paper comes up together, it is a defective product. There is no corner breakage in Taishan brand! Even if there is one, it will only be one at most! There are many ways to check whether it is a defective product, such as moisture resurgence! You can feel it with your hands! Gypsum boards are baked at high temperatures so they are very dry. And there is. Bubbles! hypotenuse! The protective paper is divided into upper and lower paper. The paper is black and the bottom paper is white (fire-proof red and moisture-proof green). There is also an inkjet code. For example, the inkjet code in Chongqing is 023010120: 201978. 203 is produced in Chongqing. The last few digits are the product number.