While visiting the fine collection at the Tartan Museum in Franklin, NC I thoroughly enjoyed the interesting stories and displays. What I didn't get around to asking was regarding the thickness of the material in the examples of the tartans that dated back to the 17 and 1800's. I was surprised to see how much thinner they were than the materials of today's "tanks". They were far more like the thickness of many of today's polyester/rayons. In looking at the number of threads per inch, it was obvious that this wasn't because of aging or wear, but that they were originally far thinner than I would have thought...a truly fine, densely woven fabric. Any idea when the heavier tartan fabrics came in?