Extended Data Fig. 2: Setup for measuring lap shear adhesion.

Two wood substrates are bonded together with an adhesive and then placed into the materials testing system. Each substrate has pin holes at the ends. One pin holds the bottom substrate in place. The top pin is attached to the moving crosshead and goes through the upper substrate. As the crosshead moves up and force is applied, a load cell measures force. The recorded force at joint failure is then divided by the substrate overlap area (1.2 x 1.2 cm here) to generate adhesion values in MPa.