Well, there is the myth that bamboo was used as armor in Japan. You’ll not the word “myth” there, actual feudal Japanese armor was made from varying combinations of leather and metal. So, that’s out.
Bamboo is used for the construction some styles of staves. It’s not armor, but you can make weapons out of the stuff, so at least there’s that. Then again, being able to make some varieties of weapons out of wood isn’t news.
Moving on, Balsa is not a good option. For those who’ve never worked with this stuff, Balsa is a very light wood. It’s used in architectural models, airplane toy kits, and to create breakaway furniture for film and TV.
If you’ve ever watched a movie where a character pulls the leg off a chair without much force, or shatters one against wall, the prop was probably made from balsa.
In addition to being a very light wood it’s quite fragile; which is what makes it ideal for stunt work. It’s also quite easy to work. You can easily cut this stuff to size with a pocket knife. If you’re making a trestle for your model railroad, or whittling pieces for a diorama, balsa isn’t a bad choice.
But, when you’re trying to stop an incoming attack, balsa is far less appealing.
The closest you’ll get to wooden armor in the real world were
shields. Interestingly, softwoods (such as pine or yew) actually made for better shields.
As I understand it, the reasoning is that softwoods better absorb force,
while hardwoods (such as oak) are more inclined to breaking. (Amusingly, Balsa is a
If you’re working with a fantasy setting, there’s no reason you couldn’t have some kind of cured light wood that can be used as the base for a practical armor. But, I’m not aware of any tree in the real world that would work.