This is a closeup of the bags before felting.
Most of us have accidentally felted something at some time in our lives. That's when you take a favorite sweater and turn it into a Barbie doll outfit when you think you're using cold water in the washer but it's actually on hot/hot. 100% Wool (and some other natural fibers) shrink when agitated in warm water. You can felt a project in a washing machine, or by hand. When you felt by hand, you can just agitate it with your hands (or a wooden spoon or spatula). You can also boil it, but not unless it's a solid color. Otherwise- it will all kinda turn to a muddy color. I know.
You can also do some felting with a steam iron. The steam will felt wool, but without agitation, it will take more time at the iron that I want to spend. It would be a good option for very minor felting or for delicate wool.
Be forewarned- if you felt in a washing machine, you should put the item in some sort of bag- I like using pillow cases. If you don't do this- you will become best friends with your plumber. The bag contains the blobs of wool and keeps them out of your plumbing. It also protects the item you're felting from attracting other fibers which can become embedded (felted) into your project. I know this, too. When you agitate the item, you do this by throwing something tough in with it- like old jeans. The first time I felted something, I threw in some old towels and didn't put it in a pillow case. My DARK knitted bag ended up with white fibers (from the towels) permanently embedded into it.
You CAN felt in a front loader washing machine, but the results can be unpredictable. I prefer using a top loader. I have a front loader. I sometimes go to a laundromat, and sometimes I beg someone with a top loader to let me play in their laundry room.
My felting bag is an old pillow case that I put a zipper into. Works great. I put a very small amount of detergent into the washer and filled it with very hot water- then put it on the super duper cycle (or whatever your washer calls it). Basically- treat it rough. I keep pulling it out, opening the zipper and looking at it until it's the size I want. Every time I pull it out, I use my fingers to shape and flatten areas that might be "rolling" or looking mis-shaped.
This is after felting. Now they need to dry. You're supposed to air dry them. Sometimes (shhh.. don't tell the felt police) I put them, in the pillow case, in the dryer to get the drying started. I don't leave the item in the dryer until it's finished drying- I just leave it in there long enough to get it past the really wet stage. Put them over a form or stuff them if possible. I made a large bag and 2 smaller ones. The small ones are stuffed with small towels and the larger one is laying on the right. It's too big to stand up and I couldn't find anything to invert it over.
And this is the big one all finished after drying for several days.
I used a heavy webbing for the straps.
The small bags have holes knitted into it for the straps. I kept opening them up as it was felting. For the large bag, I inserted grommets. It will hold more weight.
The grommets are all around the top and there are 2 closer to the bottom.