CPLR's finish is indeed brown paper - but over a conventional balsa veneered foam wing.

The theory is (and it is a valid one) is that the dimples it produces induces a turbulent boundary layer over the skin of the wing, rather than a smooth laminar flow layer. This prevents the boundary layer from breaking away from the wing until higher angles of attack - thus the wing will stall at a higher angle of attack. It is the same reason that a golf ball has dimples - it stops the air flowing over it from separating too early and reduces drag and hence increases range.

How much you would notice the difference on these models is debatable, but if anyone can he can!

James