Had this concept to draw a houndstooth pattern. Took way longer than intended but the end result seems quite decent -at least it can be edited relatively easily. Two parent threads are used for various cloning. As long as they fully fill up their clipped area, their group can contain whatever string pattern. Also the cast shadows can be edited in a similar cloning manner.
As an "in action" shot, added in a bit of displacement filtering to make the thread look a bit more organic.