Quote Originally Posted by RockyR View Post
Typically, it is a darker section of the tartan (at least 1 CM 'tall') that's used for the selvedge (if possible) and ESPECIALLY when it's a TUCK selvedge (like Lochcarron, MM, Batleys and about 10% of HOE's cloth). This way, the part of the cloth tucked back in won't show nearly as much.
Yes, which is why one of the earlier runs of the Xmarks tartan had problems as the resulting colouring issues of the selvedge wasn't properly considered, subsequent runs have been organised slightly differently.

So the answer to the question is the selvedge edge a pivot point ( or the start of the sett repeat), sometimes but not neccessarily so, the skill of the weaver and judging which colour will work best, whihc is why you should always speak to a weaver or someone experienced in tartans when designing a tartan