How to felt a wool sweater
Use these instructions to felt a wool sweater so that it can be repurposed for mittens, a pillow cover, or any number of projects.
1) Select a sweater that is at least 65% wool.
2) Wash it with your regular hot water laundry. You may want to put it inside a zippered pillow case to prevent fuzz from migrating between items.
3) Dry it in the dryer with your regular drying. If you've used a pillow case, keep using it.
4) Repeat this process until the sweater is felted to your satisfaction. The fibers in the sweater should be incorporated with each other so that a cut edge doesn't fray. Generally the more felted the sweater is the thicker and stiffer the felt will be.
5) The felting process will depend on the wool content, the weave or stitch of the sweater, the heat applied, and the agitation provided (more agitation = more felting).