There is no primary source basis for that statement re: the tenth or eleventh centuries. The term "feileadh mhor" (big wrap) is not even correct, as that was used much later (18th C.) to contrast the large plaid with the "feileadh beag" (little wrap). "Breacan feileadh" was the Gaelic name for the plaid, "breacan" basically meaning "multi-colored" in that language ("tartan" NOT being a Gaelic word, BTW)....