The planes ,that have the glass smooth finish when they are painted ,are sanded inbetween each coat or so of paint. As you sand back the paint( never deep enough to cut into the fabric and clear) the weave gets filled as you knock down the paint. you stop when the weave is filled plus a couple of coats. After the color is solid then with the right grit rubbing compound you polish the surface. It gets shinner and shinner as the sanding scratched are rubbed away. Many times thes is done to a clear top coat over the color. The control line stunt guys are masters of this. Dope is a laquer type paint very thin in pigment because it uses evaporation to dry. This si the same thing if you hear a hotrodder say he has a 20 coat hand rubbed finish. 20 coats but after each coat it is sanded so only a little stays each time.

Tom