Appearance of Birch Plywood
Premium - WISA-Birch Premium
Recommended for surfaces to be lacquered. Light and uniform outlook with face veneer made of one sheet. Some healthy knots (diameter up to 12 mm) are permitted as is slight variation in colour. Does not contain plugs or surface joints. Panels available in standard sizes up to 1525 x 3050 mm.
S - WISA-Birch Special
Recommended for surfaces to be painted with non-transparent paint. A good, uniform grade. Some sound knots (diameter up to 20 mm) and a limited number of other knots (diameter up to 8 mm) are permitted. Discolouration is permitted. Does not contain plugs of surface joints.
BB - WISA-Birch
A grade most used in technical application where sound surface is needed. Wooden plugs are used on surface veneer. In addition, minor surface defects are repaired with synthetic filler. A few sound knots (diameter up to 25 mm) and other knots (diameter up to 6 mm) are permitted.
WG - WISA-Birch
Suitable for constructional purposes where appearance is not important. Open splits, knot holes and other defects are permitted.