What are the dot shapes?

What are the dot shapes, what are their characteristics, and why should they take care of the dot shape?

A: The shape of traditional dot has square dots and round dots. Now more used is the chain point. Because of the different shapes, the perimeters of the same size are different. The round point has the largest perimeter, and thus the dot gain rate is the largest.

In the process from small to large, there are always sites that begin to overlap, as shown in Figure 2. In this part, because the overlap of the dots will cause a sudden increase in the density of the printed matter, thus destroying the continuity of the printed matter and causing the loss of certain levels of tone. For example, gradients can cause uneven transitions due to density jumps.

Of the above three types of dots, the square dots overlap at 50%, the circular dots overlap at about 70%, and the chain dots overlap at about 40% and 60%. In contrast, the image quality of the chain-shaped dot is better, because its overlap site avoids the midtones, and the overlap is divided into two, weakening the density jump. Because of this, if the image contrast is small and soft, such as a character image, a chain-shaped dot may be used; if the image contrast is large, a square or circular dot may be used.