Natural Birch Plywood, 4-40 mm* 1250-2500 mm* 1250-2500 mm Volume 30 - 120 m3 per month Thickness 4,5, 6,5 , 9, 9,5 , 12, 15, 18, 21, 24, 27, 30, 35, 40 mm Width 1250, 2130, 2500 mm Length 1250, 2500 mm Class I/III II/II II/III III/III III/IV IV/IV Class I/III plywood acceptable defects: healthy and completely overgrown knots (in limited amount) broken and ungrown knots and knot holes (up to 6 mm, occasionally) colour-matched inserts (up to 3 pcs./m2) minimal color variation Class II/III plywood acceptable defects: medullary spots natural streaks hard rot healthy knots, completely or partially overgrown broken and unfused knots and knot holes dressed with putty (in limited quantities) colour-matched inserts (up to 6 pcs./m2) putty-laced cracks Internal and external tabs – occasionally Class III/III plywood acceptable defects: natural streaks medullary spots hard rot Healthy knots, completely fused broken knots and knot holes mortar putty (up to 40 mm) surface roughness regrinding External and internal tabs larger cracks with putty