Thanks for all the replies. I'm quite aware that the Vestiarium Scoticum was found to be a fraudulent book, but many current clan tartans are derived or taken directly from what is in that book. Therefore, in some backwards way it became canon. One thing I still don't get is why is the thread count for the official Rose tartan is taken from the plate and not from the text. Personally, I really prefer the tartan described in the text.