A special substance that affects the transparency and feel of a plastic bag". Crystal shedding agents are classified into two categories: "heavy" and "light" due to different sources. Heavy crystals refer to natural mineral openings. A lightweight crystal is an opening agent made by chemical synthesis. The difference between the two is that there is a distinct difference in weight between the same volume. Or in the case of the same weight, the total amount of effective particles in the opening agent is obviously different. The light weight agent is much better than the heavy opening agent because the total amount of the particle of the opening agent is much larger than that of the heavy opening agent. Therefore, the amount added can be reduced, the total transmittance of the direct light is improved, and the transparency of the plastic bag is further improved.