[;)]I used to use balsa wood when I made my own models, I had some that were several years old and noticed they became brittle and the paint faded, so when I started selling models I switched to BASS wood as it is very durable(harder than balsa)(especially in shipping) nice to work with as far as sanding and painting. I get it in strips at the hobby shop and order a lot from Northeastern Scale Lumber(lots of sizes and shapes available)I use a lot of other misc. things like Chris said, whatever works!!!!!!