Printer's Resource FAQ

Are there any other causes of moiré?

In most instances when moiré occurs, there is simply an incompatibility with the angle of some of the patterns used. If there is moiré throughout the image, or global moiré, this may typically be solved by adjusting one of the following:

  • Change Mesh Count
  • Change Film Line Count
  • Change Halftone Angles
  • Substrate pattern (i.e. textile thread count or quality of knit).
If there is moiré in only one area, or local moiré, this may be due to a change in one of the patterns in that particular area. Some common causes for local moiré may include one or more of the following:
  • The mesh is not stretched straight throughout the screen, and the mesh angle changes in some places on the frame.
  • The specific tonal area causing the moiré may not be compatible with the mesh or mesh angle (i.e. moiré only shows up in the 30% tonal area of the image).
  • There is improper draw down of the film to the screen during exposure, causing film undercutting and dot distortion.
  • The substrate pattern or texture is not consistent throughout the piece.
There is no simple solution to solving the moiré phenomenon in screen-printing. One of the keys to identifying moiré is process consistency from tensioning the mesh, coating, filmmaking, exposure, and the substrate that is being printed. Since moiré is simply a change in one of the patterns, the more documented a screen prepress process, the more predictable the solution may be.