Printing Ink Viscosity

 There are two situations: one is that the ink of the latter color dissolves the previously printed color, causing discoloration or tailing and ghosting. At this time, the ink viscosity of the latter color should be increased; Printing Ink Viscosity

      Another situation is that the ink of the latter color cannot be printed on the ink of the former color. At this time, reduce the viscosity of the ink of the latter color.Printing Ink Viscosity

1. Hue:Printing Ink Viscosity

      Turn down the ink viscosity, the color becomes lighter, on the contrary, the color becomes darker. However, do not blindly reduce the viscosity to change the color, otherwise it will cause other problems, such as water lines, dull color, etc. In color matching, we should master the variation bias of viscosity of different colors in order to make better use of viscosity. Printing Ink Viscosity

      For example, when the primary color yellow has high viscosity, it tends to be red, while when the viscosity is small, it will show green; The green viscosity is larger than the blue phase, and the yellow phase appears when the viscosity is small.Printing Ink Viscosity

2. Water grain

      This problem is generally closely related to the printing speed. The lower the printing speed, the greater the viscosity of the ink required. On the contrary, the smaller it is.Printing Ink Viscosity

     If the speed and viscosity do not match well, water marks are easy to appear. Generally, the printing speed is basically fixed, so the water marks are solved by increasing the ink viscosity.Printing Ink Viscosity

       Another phenomenon is very similar to water marks. If you don’t carefully observe and analyze it, it’s easy to solve it by increasing viscosity like water marks, The result has no effect (or the opposite effect), which many people will ignore. I have personally contacted many printers, who often make this mistake.Printing Ink Viscosity

       The difference between water grain and this phenomenon (temporarily called “flower dot”) is that water grain shows the dot shape of very short lines, and “flower dot” It shows a round dot shape. The solution is to reduce the ink viscosity. If it is too serious, there may be a problem with the quality of the plate or ink. Reducing the viscosity can only improve the effect.Printing Ink Viscosity

3. Knife line

      Smaller ink viscosity can prevent the appearance of knife lines to the greatest extent. Especially when printing hierarchical plates, these knife lines are not printed or very small, and become more and more serious after a short time. In another case, the knife lines all appear at the position with reticulation, and they are all at the starting point.Printing Ink Viscosity

4. Ink scraping effect

     The viscosity is large and the ink scraping effect is not good (refers to scraping unclean). Especially for black ink, generally use a smaller viscosity to prevent scraping unclean.Printing Ink Viscosity

5. Poor overprint

       There are two situations: one is that the ink of the latter color dissolves the previously printed color, causing discoloration or tailing and ghosting. At this time, the ink viscosity of the latter color should be increased; Printing Ink Viscosity

      Another situation is that the ink of the latter color cannot be printed on the ink of the former color. At this time, reduce the viscosity of the ink of the latter color.Printing Ink Viscosity

6. Ink transfer

     When printing shallow screen, the smaller viscosity is very helpful to improve the transfer of ink and avoid the phenomenon of bad “small white spots”. It can be seen from the above that viscosity is closely related to many printing problems. Many problems can be solved by mastering the adjustment of viscosity.Printing Ink Viscosity