It all depends on the application, I know of a race car that using 2 layers of scrim, the paint nearly weighs as much as the bodywork, but you certainly don't want to lean on it or nudge someone whilst on track!

Thanks, I will search for some books! It's actually for a street car, nothing too fancy (nor fast).

The layup will vary again with the shape and type of panels. eg flat panels, curved panels, doors, boots etc.  There is no one guide that works for everything.  If its for road use you will want it thicker than for track/drag use.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant