Answer:
A principle of art and the universe itself, a pattern is an element (or set of elements) that is repeated in a piece of work or an associated set of works. Artists use patterns as decoration, as a technique of composition, or as an entire piece of artwork. Patterns are diverse and useful as a tool that grabs a viewer's attention, whether it be subtle or very apparent. The illusion would not work if it did not rely on an uncertainty of pattern.