I bought a Felting Needle Tool yesterday and have been playing with it this morning. I don't think I am doing it right, as the card attached to the Tool says 'no thread or glue needed' and 'both sides look good'! The first time I tried I didn't like it much (wrong fabric) and just pulled it off....! However, I had another go with some silk, and quite liked the texture and effect I achieved. It is 'punched' into black felt. A while back I pushed some air drying 'marshmallow' clay into the felt and stamped it, let it dry and painted it. Now it has some felted silk around it, but I have had to stitch it down, else it would have pulled out.
I will have another go, and try to do better next time.