Quote Originally Posted by GlassMan
And yet there is a fabulous court case in which a female member of a clan sued a weaver because he had taken the wool (in the colors of the tartan she requested) and then not woven it according to the thread count. So there would appear to be evidence for a cogent system of colorations and weaving for tartans in at least some portions of Scotland prior to the banning of the tartan. And there are also mentions in the chronicals of the time of forces raised by a clan all wearing the same tartan. So while the modern system of clan tartans didn't arise until the 19th century, there is plenty to suggest that there was such a system for at least some clans back before the proscription.

And there is also the question of why would the firms even come up with the idea of assigning tartans to clans if there wasn't an oral history remembrance of a time in which it was the case.
Interesting...what's your source on the story? Did she identify the thread count as being peculiar to "Clan MacX", or was she just upset because the weaver had simply not followed her instructions?

I agree with Matt Newsome on his point about weavers assigning names to various tartans:

Quote Originally Posted by Matt

Wilson at first assigned his tartans numbers, not names. One would place an order for twenty yards of pattern number 12 because one liked that pattern, much like one would order a style of shirt from a catalog today simply because one favors that style.

But by the end of the eighteenth century Wilsons began to identify their tartans by names, as well. But this was not an attempt to claim that the tartan belonged to, or was in any way restricted to, the family whose name it now bore. It was simply another way of identifying the tartan.[emphasis mine] We do the same thing in modern American society. The helicopter is not called “Apache,” nor the Jeep called “Cherokee,” because we believe these Native American tribes actually developed or originally operated these vehicles. They are simply fancy (by which I mean “fanciful”) names.

-- http://www.albanach.org/sources.htm
And there are also mentions in the chronicals of the time of forces raised by a clan all wearing the same tartan.
Ah, but is technically a military uniform, not necessarily a command for all members of the clan to dress alike for everday civilian wear.

Another quote from Matt is appropriate:

In 1704 the Laird of Grant commanded that all of his tenants were to be prepared to report to battle dressed in red and green tartan of broad stripes (no specific pattern is mentioned).

--http://www.albanach.org/oldtartans.html
Cheers,

Todd