Ink and template

The ink itself also needs inspection. It must be suitable for halftone printing. A general-purpose hybrid system may not be suitable because of the high content of dye fill in this system. For example, the black ink we use may be too thick for halftone printing. When the filler is too heavy, black looks darker than the desired hue. This will also cause the phenomenon of "optical network expansion". If we want to print a 50% dot, even if we control the entire printing process well, the true printing effect of this dot is even darker than 50%. This means that, on the one hand, we need to print a smaller proportion of dots in order to achieve a suitable optical value. On the other hand, we must also control the ink to a certain level to achieve the correct optical value. The effect of the dye filling can only be measured by a reflection densitometer. Without reflection densitometers, we will make many detours and make many mistakes.

To evaluate dot gains, we need to make appropriate measurements of color intensity before printing. Of course, any change in the mesh height (diameter of the wire) or the template (emulsion on the mesh, EOM) will have a detrimental effect on the effect.

The use of a relatively thin mesh, such as a 280 or 305 thread/inch mesh made of a 34 micron diameter wire, can help us to control the dot gain caused by the large ink volume. The thicker the mesh and the template, the thicker the ink film.

Similarly, the thinner EOM and total stencil height will also result in a thinner ink film. This thinner film does not appear to be so dark (less thick). In this way, since the amount of ink used is reduced, the mechanical dot gain generated during the printing process is reduced. This means that the amount of ink needed is also reduced when printing wet and wet.