American Wood Fibers www.awf.com If you are lucky enough to have a
local distibutor you can get the 50 lb bags pretty cheap. Otherwise
you have to buy a pallet of 40 bags...... at $3.00 a bag plus the cost
of truck freight for the pallet. Anyone need 2000 lbs of wood flour??
They sell 80 mesh wood flour in both pine and maple last I talked to
them.

There are other suppliers also. Talk to your local shop that sells
animal bedding (which is usually bulk sawdust) and see if their
suppliers don't also sell wood flour (as the majority of the suppliers
that I found on the web produce both products).