Wash's sweater appears when it gets a bit chilly.
More after the break...
That picture was from The Message.
These screencaps are from Out of Gas:
The Big Damn Knitters, a Ravelry Group, wanted to recreate this sweater. So, they put together a pattern (two actually!) so that you can try to make your own. Laura Wilson-Martos, of Fibercrack'd, and Maggs Kailhofer, are the main contributors.
My Photobucket Album for Wash.
Serenifly Costumes site for Wash.