The term moiré pattern comes from the French word ‘watered’ as these patterns often remind us of the splashy waves created when water splits.
Another word that relates to our discussion about patterns and rhythms in the artwork is more — an interference pattern resulting from having two meshed grids (overlayed at an angle) or two closely spaced meshed grids (separated by only). It is used in graphics card printing and other industries to create images.
When two sets of parallel lines are overlain — these are moiré patterns. Each pair of lines is more closely spaced than the next pair. If you add a set of line segments between both types of lines, a light-to-dark-band pattern appears to the eyes. The bands’ width corresponds to the lines’ line spacing and an overlap of the two lines at different angles.
But instead of these, we use moiré patterns for measuring the line spacings. The line separation is measured in terms of the width of these bands.
Another way moiré patterns can be useful is to create eye-catching visuals. Different patterns can be achieved by changing the lines’ spacing and overlapping angles.
Moiré patterns are undesired designs that may show up in photographs. In this case, the errors result from the improper screen angle alignment and/or printer’s screen rule used during the print process.
It is challenging (if not impossible) to eliminate moiré patterns; worse still, they can spoil perfectly good prints. Moiré patterns are sometimes used with the intent to create an artistic effect.
When two gratings overlap with slightly different pitches in the same plane at the intersection between the lines, a wavy pattern is called a moiré pattern. It’s usually seen when the alignment of the colors for registration isn’t correct on press. Proper printing registration methods can prevent moiré patterns from appearing on screen or paper. By knowing what causes and results in moiré patterns, printers know what actions to take to prevent these from happening.