A tartan sett is the specific pattern of colors and stripes that defines a tartan, created by a sequence of threads arranged in a particular order and repeated during weaving. This sequence determines the size, spacing, and color arrangement of the pattern, forming the distinctive design associated with a specific tartan. Most tartan setts are symmetrical, meaning the pattern repeats evenly across the fabric, but not all follow perfect symmetry. The sett is the foundational element that identifies one tartan from another.