When you overlap materials with repetitive lines, you create moire patterns.
When you look through one chain-link fence at another, you sometimes see a pattern of light and dark lines that shifts as you move. This pattern, called a moire pattern, appears when two repetitive patterns overlap. Moire patterns are created whenever one semitransparent object with a repetitive pattern is placed over another. A slight motion of one of the objects creates large-scale changes in the moire pattern. These patterns can be used to demonstrate wave interference.