There exactly 17 kinds of wallpaper pattern, no more and no less.
That might seem like a strange claim. Surely there are infinite number of possible patterns? Each pattern consists of a basic motif that is repeated. There are an infinite possibilities for that motif - but only 17 ways of copying that motif to create a pattern.
Understanding the 17 wallpaper groups can greatly enhance your pattern designs.
Not all patterns are wallpaper patterns.
Penrose Tiling, for example, is a kind of pattern that extends infinitely in all directions, but never exactly repeats.
Another example is Hyperbolic patterns.
