At the same time, exquisite packaging can not be separated from packaging printing, which is an important means and way to improve the added value of goods, enhance the competitiveness of goods, and expand the market. Understanding the necessary packaging printing process knowledge can make the designed packaging works more functional and aesthetic. Different packaging materials will have different printing processes. Collect and sort out the contents of this issue to share the relevant knowledge of printing processes.

Packaging and printing technology of paper products

1. Printing method

There are many methods of paper packaging printing, different methods, different operations, and different printing effects. The traditional printing methods are mainly divided into the following four categories:

(1) Letterpress printing

The letterpress printing means that the graphic part on the printing plate is higher than the non graphic part, and the ink on the ink roller can only be transferred to the graphic part of the printing plate, while the non graphic part has no ink, so as to complete the printing of the printed matter.

A printed matter is a relief print if the paper back of the printed matter has slightly raised printing marks, the lines or dot edges are neat, and the printing ink appears light in the center.

(2) Intaglio printing

In contrast to relief printing, the graphic part of the printing plate is lower than the non graphic part, forming a groove. The ink is only covered in the groove, and there is no ink on the surface of the printing plate. The paper is covered on the upper part of the printing plate. The printing plate and the paper transfer the ink from the concave part of the printing plate to the paper by pressurizing.

Gravure printing products, with thick ink layer, bright color, and the printing plate has the advantages of high printability, stable printing quality, fast printing speed, so it has been widely used in practice.

(3) Lithography

The image and text part of the printing plate shall keep the surface flat with the non image and text part, and the image and text part shall be covered with an oil film rich in grease, while the non image and text part shall absorb appropriate water. When the ink is applied, the graphic and text parts repel the water and absorb the ink, while the non graphic and text parts absorb the water and form the anti ink effect.

Tip: As the lithographic printing method is simple in work and low in cost, it has become the most used method in printing.

(4) Screen printing

Screen printing means that under the squeegee effect, the ink leaks from the mesh of the graphic part to the substrate, while the mesh of the non graphic part is blocked, and the ink cannot leak to the substrate, thus completing the printing of the printed matter.

Prompt: Screen printing can also be used for large area printing, and the maximum range of printed products can reach 3 meters × 4 meters or more.