I got my helmet to look smooth, not smooth like real plastic, but super smooth for being pep, all you do is get a sander block, attach some sand paper, paint grey on and let it dry, then you can see evrything uneven, or else resin looks smooth to the eye without anything ontop of it, sand down to the fiberglass on sharp pointy areas that should be smooth, then just recoat very thinly with resin, do a light sanding to remove any bumps, then paint.