I'm copy/pasting from my personal blog so don't read twice unless you really, really want to.
I used up all of my muslin fabric so I'm using this flowered khaki. It's not ideal because it is a stretch twill but it'll do. One thing you need to know if you decide to make this jacket is the arms are skinny. And that's coming from a person with skinny arms. They aren't tight but they ain't loose either. They are fine at the shoulder but they taper pretty steeply from the elbow to wrist.
I accidently cut the sleeve inside out. This is why I love muslins. I don't really have to pay attention. This was the easiest pair of sleeves ever to set.