Crepe Back Satin
Crepe Back Satin. The definition of which needed more research. Seriously. From Fairchild, p. 156 "A reversible satin weave silk...made with an organzine warp, and a crepe-twist filling." What the hell is organzine?
Also from Fairchild, p. 426 "Raw silk yarn made of two or more twisted singles that are then doubled and twisted in the reverse direction on the ply." Now, to explain that. Four filament threads are laid out, two by two. Two are spun together with an s-twist, the other two are also spun together with an s-twist. Then those new threads are spun together on a z-twist.
These organzine threads are then used on the warp of the loom, with the filling threads the usual s and z-twist crepe filling yarns, woven in a satin weave.
Also from Fairchild's description of Crepe Back Satin, "There are two or three times as many ends as picks per inch." This makes it a sumptuous fabric, with full drape, and elegant movement. It is full of texture, slinky soft on one side, crinkly on the other. The texturing is so visible you can use the same yard of fabric to create visually interesting parti-colored clothes, with the texture being the key feature. As for when it was first created...undetermined. We know the first references to crepe fabric in Europe are from the 19th century. We also know that the Chinese have been weaving crepe for centuries before that. It probably didn't take long to experiment with satin weave and crepe yarns. But when did historical spinners decide organzine was a thing? Another mystery to be discovered later.