Bates Crates are built using only hard-woods. I've tried softer hard-woods, like Aspen, and it didn't work out. I've also used Cedar and it looked nice, but I just wasn't happy with it.
For now, all crates are made with Maple. Future plans include doing one-offs experimenting with different types of wood.
All woods are stained and sealed with a marine grade polyurethane so they will hold up to whatever weather you're up against!