Carved Wood

While more expensive than plywood, bamboo or dimensional lumber, frames made from carved wooden tubes (or even monocoques) do exist.

Advantages

• directional strength (somewhat like CF) allows for stiff yet vibration-absorbing frames
• good strength to weight ratio
• potentially eco-friendly
• resistant to denting due to thicker walls
• looks and feels awesome (subjective)

Disadvantages

• needs thicker tubes
• very difficult to use well
• easily damaged by moisture unless specially treated
• very expensive due to labor (and sometimes exotic woods)