Flexo printing is a type of relief printing, and the printing plate material is a flexible resin plate.

The three key areas of flexo printing are trademark labels, plastic flexible packaging, and folding cartons (such as milk cartons).

Complete flexo printing units are generally rotary machines.

Offset printing is lithographic printing and uses PS plates as printing plate materials.

Books, paper packaging, etc. generally use offset printing. There are two types of flatbed machines and rotary machines.

There are two other popular printing methods - gravure printing or silk screen printing

The main target of gravure printing is also plastic flexible packaging, but the ink of gravure printing is thicker and the printing effect is softer than soft printing. The seal should be good. For example, instant noodle packaging bags and cigarette boxes are basically gravure printing;

Compared with flexo printing, gravure printing has a long plate making cycle, high cost, and pollution, so it is suitable for long-run printing; Flexographic printing has low cost, simple production, and is a green plate making, but the printing volume of flexographic printing cannot be too large.

Silk screen printing is generally used to print special materials. Such as cloth, metal, leather, and are also often used for post-printing special effects.

Of course, in real applications, there are usually situations where a variety of printing methods are combined.

Any printing principle is inseparable from color separation and dots. Many things can be achieved in different printing methods, but the specific process arrangements must be based on the quantity of products, economic costs, and customers. It depends on the requirements and the length of the production cycle.

Flexo printing is a direct printing method called flexographic printing due to the use of elastic, raised image printing plates. The printing plate of the flexo plate is glued to the plate cylinder, and the printing plate is inked by an engraved metal anilox roller. Because the flexographic plate is very elastic and can transfer liquid or grease ink to almost all types of materials, flexographic printing is light pressure printing.

According to the characteristics of flexographic printing, when selecting originals, you should choose originals suitable for flexographic printing:

1. Design various patterns suitable for flexographic printing, such as lines, colors, etc. It is better to use spot color for blocks.

2. Excessively small text and lines (especially reverse white requirements) are difficult to achieve with flexo printing and should be avoided during design.

3. The design should avoid strict registration requirements.

4. The characteristics of the printing machine and whether the ink can truly restore the original should also be considered. For half-tone originals, avoid designing and selecting large-area high-gloss originals and pictures.

5. High-magnification reduction and enlargement should be avoided in terms of original size, because these will cause the loss of levels.

Flexographic printing has unique flexibility, economy, is beneficial to protecting the environment, and complies with the hygienic standards for food packaging printed matter. This is one of the reasons why the flexographic printing process is developing rapidly abroad. However, judging from the current situation in our country, offset printing is relatively popular, and gravure printing has also occupied a large market in the packaging industry. However, the technology of flexographic printing started relatively late, although it has indeed made progress in recent years. Great progress has been made, but there is still a big gap with the international advanced technological level.

From the perspective of original design and plate making process, the flexographic printing process is its own system and has its own unique features. The plate making process is basically as follows:

Original → Electronic Color separation or photography → positive and negative pictures → back exposure → main exposure → development and rinse → drying → post-processing → post-exposure → plate mounting

Compared with offset printing, there are main differences in the following aspects:

1. Reproducible color value range. Offset printing is 1 to 99 (or 2 to 98), and flexo printing is 3 to 95.

2. Expansion of outlets (50 locations). Offset printing is 15-20, flexo printing is 30-40.

3. Add the number of network lines. Offset printing generally has a maximum of 175 lines/inch, while flexo printing generally does not exceed 150 lines/inch.