[TCML] Coil forms, any good?

[Tesla]

Hi all.

I have just struck a little bit of gold, I now have more or less 
unlimited supply of
coil forms in glass fabric, cotton fabric and paper. The resin in 
these forms are some of the
following: Phenolic, Epoxy, Melamine, Silicone and Polyester.

Are they all good for winding coils on or are there some that i should avoid?
Also if they're good, does the thickness of the wall(RF losses) 
affect the coil performance
with these materials?

Of course i have seen several on the web using fiberglass so i guess 
that should be ok
but what about the other materials?

Any input appreciated as i can get any diameter in any length for 
free. Lucky me....=)

Thanks!
/Matt
www.tesla.nu (in Swedish)