My supplier of choice is Sutherland Felt at 248-280-0450.

On Wing Riggers I am using a dense SAE F7 grade material that is 80%
wool.

This material is also available at www.mcmaster.com. Though McMaster
is more expensive, it may be more convenient to buy small quantity
from them.

It might also be of interest to tell you that I did trials with a
number of different adhesives. I found polyurethane adhesive to be
by far the best because it soaks a little ways into the felt and
provides a very solid grip. Gorrilla Glue is one brand of
polyurethane adhesive.

Steve Koerner
www.wingrigger.com