Thank you Artlady. The yarn came with no information but I could tell it was a nutural fiber. In the wash the fiber was very long and hairy. They felted very nicely though.
I felted them to fit my feet then put them through the rinse and spin. They were then just short of my back heel and I wasn't able to pull them back into place. If i make more I'll be sure to remember to stop felting just before they reach the correct length.
That's doesn't matter though. They were perfect for my daughter. Now with the wool socks I made for her and wearing these too, her feet should never be cold.
The pattern states to double strand but this was thick enough that I didn't need to.