A • Siberian Larch • top quality • filled-in surface without repairs • lamellas without Gaps • stable colour • sanded
B • Siberian Larch • visible quality • knotholes repaired with branches of various sizes • wood putty to fill the gaps • without colouring • minimal gaps in core • sanded
C • Non-visible quality • repaired knots of larger size • wood putty to fill the gaps • sanded
D • Non-visible quality • without repairs • knot holes may be present • gaps between lamellas • sanded