Line count and Angle

Contents

1. Angle of the halftone
2. Line count of the halftone
3. Summary

Angle of the halftone

Appearance of Moire

These are all printed images with the same line count, but each one is rotated by 5 degrees.
Moire is occuring due to the angle.

Mesh and dot angles

The relationship between the mesh and the halftone can be reproduced by overlaying the screens.
Overlay periodic patterns like this, the striped patterns appear.
This pattern is called moire.
Moiré is most pronounced when the periodicity(0˚) is the same.

As the angle changes, the spacing between the screens narrows, making stripes less likely to appear.
Just like with this screen mesh, there is an optimal angle between the mesh and halftone dots where stripes are least likely to appear.

Line count of the halftone

Actual printing outcome

When setting the line count for the emulsion screen printing, it is common to set it to less than 1/4 of the mesh count of the mesh being used.
However, GOCCOPRO’s digital screen making allows you to make screens by directly perforate holes on the screen, so the line acounts can be as fine as 1/2 to 1/3 of the mesh count to be feasible.

These are the results when the same data is printed at different line counts.
The angle is set appropriately for the line counts.
The 40-line count has slightly lower reproducibility of the fluffy texture, but the gradation of tone are clearly reproduced.
On the other hand, the 60-line count shows some blown-out highlights under the eyes and under the beak, but because the lines are finer, the fluffy fur is also reproduced clearly.
If you want to achieve beautiful gradations, 40-lines are better than 65 lines, for expressing delicate halftone 65-lines are recommended over 40-lines.
However, which setting is more appropriate will depends on the design and is also influenced by the creator’s preference.
It is recommended to test the results in advance

Summary

Recommended angle settings

When performing screen printing, set the line count according to the design and desired outcome.
The most important thing is the angle for the line count.
Below is a summary of recommended angles for different line counts.
*This table is based on using the GOCCOPRO for the screen making.
The quality of the results depends on personal preference. So test printing is recommended.