Most of the commodities in the market are packed with plastic film. Most of them need to display product information on the surface. Here, they need to be printed on the film. Plastic packaging has single-layer and composite film. They correspond to single-layer surface printing and composite inner layer printing respectively. For plastic film substrate, these two printing methods are gravure printing, so what is the difference between them?

The so-called surface printing refers to printing on the surface of the film. The printing ink is exposed outside the product. Therefore, it is required that the ink has good adhesion, considerable wear resistance, sun resistance, frost resistance and temperature resistance, and excellent quality in gloss. The main substrates are PE and PP.

Inner printing is a printing method that uses the reverse graphic printing plate to transfer the ink to the inner side of the substrate film and present the positive graphic effect on the outer side of the substrate. The utility model has the advantages of bright color, no fading, no fading, moisture resistance and wear resistance. With the wide use of composite materials, the internal printing method is selected to avoid ink fading and reduce the risk of printing ink pollution to packaging contents.

The color sequence of surface printing is white ink first and black ink last; On the contrary, black is the first color sequence, and the arrangement of special printing color sequence also needs special treatment according to the situation.