from
http://www.lionbrand.com/faq/254.html=
Basically, here are the steps:
1. Wash in warm water with soap.
Why soap? It actually speeds up the felting process!
Felting can often be improved by adding baking soda or washing soda to the water!
What about the rest of the laundry? Throw it in! Though it may not be recommended in the directions for all felting projects, washing felted things with other laundry can speed up the process! Why? Agitation is another important element for the felting, and the rest of your laundry does just that (be sure to check out the TIPS below)!
2. Rinse in cool water
Rinsing in cool water "locks" the fibers in place. Most people have a warm wash/cool rinse setting on their machines (easy, huh?)
3. Air dry
If you are making a piece that needs to conform to a particular shape (say, a rectangle piece for a bag), it will likely be lopsided when it comes out of the dryer. Adjust it to the right shape BEFORE you let it dry (remember: once felted, felted for life) or pin it into shape on a blocking board and let it dry there – yup, blocking is important in felting, too