Maybe this photo will give a better of idea of what felted wool should look like.
There is also a machine that can be purchased to do the felting or you can do it by hand.
I was told by someone that uses wool for rugs that Goodwill will sell wool clothing in large bundles and it is much cheaper that way than purchasing things piece by piece. Not sure if that is all stores but they will do it here.
You can also make felt from a wool sweater by doing the same thing.