The trunk should be thickest at the base and narrow toward the apex. Negative Space:
The soldier later became a noted bonsai artist in Oregon. And to this day, collectors of first-edition Bonsai Techniques I (1973) look for one thing: a tiny, almost invisible smudge on page 87, next to the root-grafting diagram. That’s Naka’s own thumbprint—ink from his final verification, pressed there by accident during the proofing stage. He refused to correct it. "Proof that a real hand did the work," he said. john yoshio naka bonsai techniques 1 verified
In Bonsai Techniques I , Naka dedicates an entire chapter to water because more bonsai die from bad watering than from bugs. He provides a verified, foolproof method: The trunk should be thickest at the base