All the coated steel plate experiments of Himei Metal are carried out at an ambient temperature of 25±2°C, and the back and incision ends are sealed. The surface of the coated steel plate is not allowed to have obvious defects such as scratches, black spot impurities, embossing, folding, holes, scratches, line stripes, air bubbles, etc., and plate size deviation. The original impurities are allowed to have a diameter of ≤0.3mm, and 2 places are allowed per square, but the distance between each two shall not be less than 500mm, and beyond the range is not allowed. The product should be stored in a dry and ventilated place, and it is not allowed to contact with moisture, chemicals, etc. The product should be stored away from sunlight, which will cause the product to change color and age.