It’s a rayon/nylon/angora blend that got a little felted, which is why I think it was at the thrift store. It’s marked as a size large, but clearly is not that big as it fits my XS self fine. And it didn’t get felted to point it won’t stretch – plenty of stretch, which isn’t always the case with felted items.
So, I cut off the neck.
Folded it with shoulder seams matching to cut the center front into a V neck, then bound it with 2 inch satin ribbon the same way I did this neckline. (IMPORTANT – since satin doesn’t stretch, measure the neckline to make sure your head fits through without stretching before doing this).