Three-Ply Panels
Grade A:
Surface sanded; free from cracks and joints; healthy fully grown branches; single black or black-edged branches up to a maximum of 15 mm diameter; patches permitted on the blacks branches; free from medullary tubes (except for isolated ones); healthy wood; staining and fungal infestation not permitted; almost box-free (light box allowed) so that the overall impression is not disturbed; joints laminated.
Grade B:
Surface sanded; free from joints; single fine cracks allowed; black branches and patchy branches (but no accumulations); isolated medullary tubes allowed. Resin galls up to 5 x 50 mm; light box; small isolated bark ingrowths up to about 1,5 cm are allowed; joints laminated.
Grade C:
Surface sanded; holes in branches repaired; small joints may occur in individual panels (max. 2-3mm); otherwise no particular quality requirements; joints laminated.
For storage and further processing the following should be noted:
Despite the advantages which have been specified, it must be borne in mind that the single-ply and multi-ply natural wood panel is solid wood. This continues to live after processing, i.e. it adapts to the ambient climate (e.g. as a result of increase in ambient moisture, the wood naturally absorbs moisture and this results in changes in dimensions).
The panels must therefore be suitably stored and the construction of the furniture must be matched to the specific properties of the solid wood.
In a uniform room climate which is not too dry, any variations will remain small. Nevertheless, slight warpage and fine cracks may appear on the surface; this is natural with living materials and is not attributable to production faults.
