The glossiness of blister packaging refers to the degree of specular reflection on the surface of the packaging, expressed as a percentage. The higher the glossiness of the packaging, the more its surface can reflect light like a mirror, and the brighter its appearance characteristics. In fact, in addition to specular reflection, there is also diffuse reflection on the surface of the packaging, which reduces the glossiness of the packaging. The higher the glossiness of the packaging, the brighter the ink color of the printed product, and the better the visual effect of the ink color. It can be said that the smoother the packaging, the higher the glossiness, and the higher the glossiness of the printed color. The glossiness and smoothness of the packaging are closely related, but glossiness is not smoothness. The glossy surface of the packaging is not necessarily a smooth surface. From the perspective of the glossiness of the packaging, it is very practical to choose a suitable packaging for printing according to the characteristics of the printed material. For example, for books and periodicals with text as the main layout, it is advisable to use paper with normal glossiness to avoid reflection, so that the eyes will not be tired after reading for a long time. For the layout with pictures as the main printing, it is advisable to use PVC PTE PP with high glossiness to make the ink color of the printed product uniform, thick, bright and pleasing to the eye.

　　1. The Relationship Between Gloss and Color Rendering of Packaging Boxes

　　The gloss of a thermoformed packaging box refers to the degree of specular reflection on the surface of the box, expressed as a percentage. The higher the gloss of the packaging box, the more its surface can reflect light like a mirror, and the brighter its appearance will be. In fact, in addition to specular reflection, there is also diffuse reflection on the surface of the packaging box, which reduces the gloss. Packaging boxes with high gloss also have more vibrant ink colors and better visual ink effects. It can be said that the smoother the packaging box, the higher the gloss, and the higher the gloss of the printed colors. The gloss and smoothness of the packaging box are closely related, but gloss is not smoothness. A glossy surface of a packaging box is not necessarily a smooth surface. From the characteristics of the gloss of the packaging box, it is of practical significance to choose the appropriate packaging box for printing according to the characteristics of the printed matter. For example, for publications with mainly text, it is advisable to choose paper with general gloss to avoid reflection, so that the eyes will not be fatigued even after prolonged viewing. For printed matter with mainly illustrations, it is advisable to use high-gloss PVC, PTE, and PP to make the ink color of the printed matter uniform, thick, vibrant, and pleasing to the eye.

　　2. The Relationship Between Smoothness and Color Rendering of Packaging Boxes

　　Thermoforming smoothness is a technical indicator for evaluating the degree of concavity and convexity on the surface of a packaging box. Thermoformed packaging is a physical quantity that represents the degree of flatness, smoothness, and uniformity of the surface of a packaging box. It is measured by the time it takes for a certain volume of air to flow from a certain pressure through the surface of a packaging box test sample and a smooth glass surface under certain vacuum conditions, and the unit is seconds. The higher the number of seconds, the better the smoothness of the packaging box. The better the smoothness of the packaging box, the more uniform and complete the contact between the paper surface and the printing plate during printing, and the more complete the transfer of the ink layer on the printing plate (letterpress) or rubber blanket, and the better the color rendering effect of the printed matter. Conversely, packaging boxes with poor smoothness have uneven and incomplete ink transfer, and the paper surface has strong ink permeability, resulting in poor color rendering, often causing the ink color of the printed matter to be mottled and light. Therefore, for printing fine products, the finer the lines and the smaller the diameter of the dots, the better the smoothness of the packaging box should be used for printing, so that the reproducibility of the original can be improved.

　　Thermoformed PVC, PTE, and PP, as the main raw materials for printing, their performance determines the quality of the printed ink color. Only good-quality raw materials can achieve better color rendering effects of the printed matter. Therefore, correctly understanding the relationship between the performance of the packaging box and the color rendering of the printed matter, and reasonably selecting the packaging box for printing according to the characteristics of the printed product and process conditions, is of great practical significance for improving product quality.