I found pretty piece of painted very sheer silk in a shop in Turkey. I did not want to cover it in felt, so laid on circles of merino roving. It was very large, so I wrapped it all in a roll covered with a damp towel and felted it in the tumble drier. The colour in the silk bled leaving it paler than originally, but still pretty.
I like the interesting textures in the silk as the fulled wool draws it up. And also the fact way the wool gives the shawl texture and structure when you wear it, yet remains light.