The dots of the plate image are not normally reduced, spread, or blurred. This is called the paste version. In fact, they are in the opposite form of a pair of failures - flowers and paste, such failures are the most common phenomenon in lithography.
A flower version
When printing at the outlets, the internet point of the printing plate is reduced, empty, and disappeared, and it is called a flower version. Thin lines and text disappeared on the plates, also called floral editions. When the flower version occurs, the high-profile fine dots will soon be lost. In the field printing products, due to the destruction of the base-based lipophilic foundation, the phenomenon of whitening occurs, which is also called the floral version.
The main cause of floral patterns is fountain solution and friction.
1. First, it refers to the amount of fountain solution and the acidity of the fountain solution. The amount of dampening solution is large, which will promote the emulsification to increase, which will make the outlets narrow and the fine outlets to be lost. The fountain solution is highly acidic and produces similar results.
2. The friction of the printing plate is caused by the contact between the water roller, the ink roller, and the blanket. The amount of friction depends on the degree of parallelism between them, the size of the pressure, and the condition of the surface. The friction that promotes printing of the printing plate mainly depends on the water roller, and the friction between the blanket and the printing plate is the greatest. If the paper during the printing process is severe, it will exacerbate the friction.
Second, paste version
The characteristics of the stencil are: the layout of the outlets is enlarged and distorted, and they are merged and annexed to each other, which makes the level of prints unclear. It is mainly reflected in the low-key part of the image.
There are many reasons for producing paste, which is mainly due to water, ink and pressure.
1. There is a close relationship between water supply system control and pasteboarding. With a small amount of water, the ink can easily expand, spreading the dots and creating a paste. Lose a large amount, increase ink emulsification, can also cause paste version. Because of the poor oiliness of the emulsified ink, which floats freely to the fountain solution, it first expands outwardly at the low-medium-medium outlet to form a paste.
2. Too much ink is one of the basic causes of paste. Because the ink volume will inevitably cause the expansion of outlets, over time, it will create a paste version. Too thin ink is also the cause of the weight of paste. The thin ink flow is too large and after squeezing it produces a paste pattern.