2.2.2. Surface bonding strength
The bonding strength between the fancy veneer and plywood was evaluated with a Universal Testing Machine (UTM, Hounds Co.) in the tensile mode. Samples were cut at 50 mm 50 mm (length width) and a knife mark of 20 mm 20 mm (length width) was made on the surface (fancy veneer face) to
a depth of 0.5 mm. We bonded the upper device of UTM and the surface knife mark with hot-melt adhesive. Another face was bonded to the underneath of the device like the internal bonding
strength test specimen. The tests were performed at a crosshead speed of 2 mm/min (Kim and Kim, 2005b).