Arguably the best way to make lightweight, warp resistant and stable tail surfaces is by gluing together (laminating) thin strips of A-grain balsa around a (waxed) cutout form of the structure outline. Hobby Specialties offers for your building convenience, a variety of commonly used sizes of laminating strips. These will typically be in the 4.5-6# density range.

For orders outside the US: If you only get "Global Express" as a shipping option for a gozillion dollars, go ahead and place the order along with a note saying you want "Global Priority" shipping instead. I will make the adjustment on my end PRIOR TO CHARGING YOUR PAYPAL ACCOUNT.