The relationship between ink and dot gain

Many factors in the ink such as pigments, tackiness, viscosity, and resin are all related to dot gain. The strength of the ink - its color strength - plays an important role in the dot enlargement. The ink is pressed by the printing plate and the blanket, and then squeezed between the blanket and the paper. The ink layer formed after two extrusions is usually very thin. The color intensity of the ink depends in part on the pigment in the ink. Pigments are often the most costly part of the ink. However, reducing pigments also reduces the tinting strength of inks. When the ink layer is thick at the time of printing, dot network expansion will occur. The coloring power of the ink is high, and the printed ink layer is thin, so that the desired ideal color can be obtained.

In the control of network expansion, ink adhesion is also very important. The higher the viscosity of the ink, the smaller the dot gain. However, if the viscosity of the ink is too high and its degree exceeds the strength of the paper, the paper will “fluff” and even severely tear the paper.

Viscosity, also known as the flow properties of inks, depends primarily on VanWater and pigments. Of course, temperature and water also affect viscosity. At low temperatures, the viscosity of the ink is high, and the dot gain is low; at high temperatures, the ink viscosity is low, and dot gain is high. As we all know, in the printing process, the ink viscosity changes with the temperature.

In plain printing, the feed rate of water has an effect on the viscosity of the ink and the dot gain. When the ink absorbs water during the printing process, the viscosity decreases and the viscosity decreases, which affects the dot gain. Too much water will reduce the viscosity of the ink and increase the dot gain. As a result, overprinting will also occur. Conversely, if there is a lack of water, the viscosity of the ink will increase and paper fluff will occur.

According to another study, soy-based inks have less effect on dot gain than petroleum-based inks. As the degree of expansion of outlets has decreased, the contrast of printed products has also increased.

Source: PACK.CN