I found some silk scarves that I had bought cheaply in India, and tried felting in fine wisps of merino wool. They felted really easily, and I love the way the silk crinkles up and develops a great texture as the wool shrinks. Of course the finished length of the scarf is shorter too. Pictures cannot capture the light softness of the silk and wool, and they are delicious to wear.
Blending with the original scarf colours, I did one in soft cream brown and yellow, for myself, and a more funky bright pinks and purples, with a detachable flower brooch, for my daughter.
This technique of felting wool into silk is called nuno felting.