I have quite the stash of felted wool sweaters already, but I have some crafty holiday ideas so I wanted some more holiday colored ones. I went to the Goodwill and found a nice bright red one. In addition, I found a lavender cashmere one, which is not a holiday color, but I have a hard time passing up cashmere. I also had a few wool sweaters that were in my "need to felt" pile from last winter. This included a pink/white fair isle, a gray cashmere (yum) cardigan, a blue checked sweater, and the body of a yellow/brown cable knit striped sweater. I also inherited a plaid wool skirt from a friend so I tried to felt that as well.
I always use my washing machine to felt sweaters. I have a standard top load. I don't think front load and high effeciency washers will work for this.
I stick my sweaters in zippered cloth bags by color. The pink and red one together. The gray and purple one together. The sweaters shed a lot of fiber so putting them in zippered bags prevent the fibers from clogging my washer. It also prevents red fibers from getting on a blue sweater, etc. The bags I use are pillow covers, some decorative, some white bed pillow covers. I get these at the thrift store. If I run out of bags I will use a mesh laundry bag, but prefer the zippered cloth ones.I did use a green mesh one in this load, here are all my bags ready to go.
The other thing I've started doing recently is saving the fibers from the sweaters that are in the zippered bags. I call them felt boogers. I have a felting machine (also called an embellishing machine) and can use these for felted art. I just have a quart size zipper bag by the wash machine and stuff them in there. I have a separate zipper bag for threads from my dyed fabrics.
Here are my results. These are on a standard size bath towel to finish drying. They look like kid size sweaters now.