ISO 13609:2021 pdf download – Wood-based panels — Plywood — Blockboards and battenboards. 4.2.2 Thickness The thickness of plywood shall be greater than or equal to 3,0 mm. 4.2.3 Surface appearance The surface appearance of plywood shall be controlled. Surface appearance of the face layer shall satisfy the criteria defined for class II, as given in ISO 2426-2:2020, Table 1 or in ISO 2426-3:2000, Table 1 or in ISO 2426-4:2018, Table 1. 4.2.4 Joint Jointed plywood is not permitted when used for surface layers. 4.2.5 Direction The direction of the grain of the veneer glued to the core shall be...