For PEEDYC: The quote on the link didn't survive submitting the post.

The link did not find the page. I'd like to read it.

The 12th Duke of Argyll stated that there are only 4 Campbell tartans: Ancient, which he wore, and those of Breadalbane, Cawdor, and Loudoun. His son, the 13th Duke, current chief of the name and arms of Campbell, and Scotland's senior peer, quotes his father on this matter. He does say that he knows of no reason not to wear those others created by weavers, but if your intent is to indicate connection to the clan you will follow his example.