The formation of network expansion causes and classification

Dots are the basic unit of ink adhesion and play a role in transferring tunes and organizing colors. Dot enlargement refers to the dot gain on dots printed on the substrate relative to the dots on the color separation sheet.

The formation of outlet expansion

1. According to the printing outlets change classification:

1 Normal expansion. This kind of printed dot enlargement is allowed, which means that the dots are expanding normally, with high density in the center of the dots and low density of edge locations.

2 ghosting outlets. This kind of printing dot enlargement is not allowed. If there are dot ghosts during printing, the dot color effect will be seriously affected.

3 There are no regular dot gains. When there are no regular network expansion points, there is no rule in the printing outlets, and the outlets will be expanded in all directions. At this time, it is easy to get stencils and dirty prints, affecting the quality of printed products. The network expansion scope does not exceed 15%, 12%, and 10%.

2. According to the expanded status of outlets:

1 Linear enlargement means that the edge of the printing dot has a direction of expansion. Originally, the printing dots are square, round, prismatic, and chain-shaped. The linear enlargement means that dots expand linearly toward a certain aspect.

2 The printed dots are expanded in all directions. The enlargement of the dot area is generally proportional to the length of the edge of the dot. In other words, the dot area is large, and the length of the edge of the dot also increases at this time.

3 The increase in density is proportional to the area of ​​the printing dots, the density increases, the ink color is large, the ink color is large, and the dot area is large.

Dot expansion

1. Mechanical dot enlargement: The ink attached to the metal plate is deformed and expanded by the pressure of the printing press.

2. Optical dot enlargement: Due to the light reflection effect, when the light reaches the surface of the dot, surface reflection occurs, and the ink penetrates into the edge of the dot in the paper, forming a diffusion vignette. This kind of reflection vignette forms a hue. It is the same as the mechanical dot enlargement during printing.

These two types of dot-extensions have a detrimental effect on printed materials to varying degrees and destroy the balance of the picture. In order to make a true reduction of the outlets on the printed matter, it is necessary to control the delivery process of the outlets, that is, a printing plate, a blanket, and a substrate.