Cracking on the outer side of the cardboard indentation line. This is because the indentation line is too deep and the width of the indentation die is not enough. If the inner side of the cardboard cracks, the paper fibers may break due to excessive die-cutting indentation pressure. Therefore, appropriate die-cutting pressure should be applied and a slightly lower indentation line should be used, or the indentation line should be widened based on the thickness of the cardboard board. The indentation line is not clear. There are two situations: the die-cutting pressure is unstable or too small, and due to wear or looseness of components, the stroke of the imprinting drum or flat plate during each pressing process varies from light to heavy. When the pressure is light, the product indentation line may not be clear. At this time, the configuration needs to be repaired to restore the balance of pressure; The second issue is that if the rubber strips are pasted too tightly or too thick, it will cause high resistance during compression, affecting the average and stability of pressure. Therefore, it is necessary to pay attention to the appropriate density and thickness of the rubber strips. The cardboard box is skewed. Due to the inappropriate thickness of the indentation steel wire knife, if the steel wire knife is too thin, it will cause insufficient indentation force on the paper surface at the crease line of the printed product when die-cutting corrugated cardboard. When folding the cardboard box, the paper surface at the crease will bulge due to "paper accumulation", resulting in the product being tilted after folding. If the thickness of the die-cutting product is increased, the thickness of the steel wire cutter should also be increased, so that the crease edge is not easy to accumulate paper.