I wear Macleod of Lewis (i.e. Loud Macleod), the only tartan that really gives Buchanan a run for its money. Although I do have clan affiliation, I would likely wear this tartan even if I didn't, because I feel it matches my loud personality! I would resent anyone that thought I had no right to wear it, but, that said, I think it is a good idea to have some vague idea of the clan you are unofficially "joining" when you wear their tartan. Technically, all you had to do to join a clan was to swear allegiance to the clan Chief (or marry into it!), so swear allegiance if that makes everyone feel better.

Be well,