Collapse Cloth with 60/2 Silk and 30/1 S-Twist Wool

Just off the loom: a one-yard-long sample of vertical pleats in black and white. (Can't get enough of the beauty of simple plain weave in black and white! My inspiration is the work of Ann Richards , author of Weaving Textiles That Shape Themselves .) This sample is for a coat I hope to make, so I made a warp of 11.5 yards in length. On the loom, this fabric is 45.5" in the reed but, after washing in hot water and dishwashing liquid, it collapses to about 20" wide -- a shrinkage of more than 55%. The warp is alternating ends of black and white 60/2 silk. For the weft, I wove horizontal stripes, alternating between natural and black 30/1 S-twist wool bordered by a one-inch-long stripe in black 60/2 silk. Because the weave is very open -- at 32 ends per inch and about 30 picks per inch -- the yarns have lots of "wiggle room" to collapse in the wash. This means that the overtwist wool draws in horizontally, making vertical pleats, while the 60/2 silk weft r