Just recently bought a bamboo cage for the Hwamei. The one I bought did not have any kind of treatment to the wood (no paint, no vanish, no protected oil). I forgot to take the picture of the before untreated bamboo cage, but here is the final finish after a few coat with Formby's tung oil finish (natural color), a coat of Watco danish oil finish (natural color), and thin layer of Helmsman spar urethane for extra protection against water and sun UV ray damage. According to few woodworkers I asked, one of either three products above is enough to turn raw bamboo cage to a beautiful one and fully protect the cage from water damage; however, I like to protect the bamboo cage from UV ray also. Depends on type of bamboo to make the cage, even when I use natural color coat (no stain color to the wood), this cage turn out quite beautiful with little darker color than before untreated, but my other cage did not turn darker, just shinier.