Those that want to know more I thoroughly recomment Dr., Elizabeth Wayland Barber's The Mummies of Ürümchi (New York: W. W. Norton; London: Macmillan, 1999).

I had the pleasure of meeting the author some years ago and to discuss the Urumchi tartans and in particular, their construction which are a mixture of twill and plain weave. Dr. Barber was puzzeled by reason for the difference, I observed that we see the same in historic Highland tartans and that this difference seems to have been due, in part at least, to gender use and that women's clothing was often made from plain weave tartan. Dr. Barber took that idea away but I don't know if she ever persuded it.