• Rustic grade oak is characterised by the number of knots and colour unevenness.
  • Rustic oak has unlimited number of fine and up to 60 mm knots.
  • Fallen knots are being filled with special oak filler.
  • Small hallows are acceptable.
  • The central core is allowed.
  • Oak grain pattern is heavily exposed.

NATURE grade

  • Nature grade wood product range includes natural-looking wood planks.
  • Natural wood-grained pattern is clearly visible.
  • The colour tones show a set of knot locations, unlimited number of small knots.
  • Allowed up to 20 mm knots, which are filled.
  • Sapwood, central core, cracks and knots on edge are not allowed.


  • Select/prime grade oak wood is carefully selected.
  • A natural wood tree-ring pattern and medullary rays are visible.
  • Single knots up to 5 mm are allowed with no fillings.
  • Any other defects are not allowed.
  • Wood pattern and colour tone depends on a wood-tree pattern, what is typical for the oak wood texture.