While I'm still thinking about diamond twill, I figured that I would post some diagrams of the weave patterns of the Wollstoff's and Naturtuche's twills, since Sanne has so thoughtfully drawn some for me. They might be helpful for people interested in doing comparisons to the "diamond twill" weave diagrams so often seen on web sites and in books. To the left is a diagram of the warp and weft patterning of Wollstoff's wool blend diamond twill. To the right is a diagram of Naturtuche's worsted diamond twill.
Below them both is a standardized diagram of 2/2 broken diamond twill from the Complex Weavers' Medieval Textiles website.
Clearly the Naturtuche worsted and Wollstoff twills are both broken diamond twills. (Though the two-toned Naturtuche twill looks more like the Complex Weavers' diagram than does the fabric Sanne has diagrammed here.)
I am far from expert in thread counting, reading pattern drafts, and other skills associated with weaving, but it seems to me that the Naturtuche and Wollstoff twills have sides of different thicknesses than the "standard" pattern drafts. It also looks as though the Naturtuche diamonds are a bit longer, a bit less like a "square" turned on its corner, than the diamonds in the Wollstoff twill. For that reason, I think the Naturtuche diamond twill looks a little bit more like a period diamond twill. (Which is fortunate, considering that Wollstoff does not ship to the US!) Hopefully, I can gather swatches of diamond twills from the two other sites, the Danish one and the Russian one, and make a real decision whether to buy any fabric, and if so, which one to select.