Originally Posted by late
Wool shrinks, dry clean. In practise, this means you want to wear something under it so you don't have to wash it so often.
I had a sweater that was a bulky and heavy men's XL. My wife washed it in th washer; and it became her sweater. She did it again, and we gave it to a kid. It was almost bullet proof at that point; very much like the old fashioned expedition sweaters they used to make. Those sweaters weighed one to two POUNDS.
she probably washed it in warm water and then threw it in the dryer. Heat and agitation are the two things that shrink wool, so - machine wash GENTLE in COLD water. AIR DRY. Never machine dry.