Birch natural plywood, 4.5-40 mm 1250-2500 mm 1250-2500 mm ext

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