There are various styles of wood floor: solid, engineered, strip, plank, parquet and acrylic mpregnated. The appearance of the wood determines its grade. In another word, grade is the natural look of the wood (knots, streaks, shakes, wane – i.e. all its natural features that haven't been changed by man.)
Here to have a quick look at wood grades:
Grade A is free of defects, though it may haove minor imperfections.
Grade B is almost clear but contains some natural characteristics such as knots and color variations.
Grade C has a variegated appearance, light and dark colors, knots, flags and wormholes.
Grade D is rustic in appearance and emphasizes all wood characteristics of the species.
First grade wood has the best appearance, natural color variations and limited marks.Second grade wood is variegated in appearance with varying sound wood characteristics of species.Third grade wood is rustic in appearance allowing all characteristics of the species.
The angle at which a board is cut determines how the finished product looks. Wood flooring is either plainsawn, quartersawn or riftsawn.
Plainsawn is the most common cut. The board contains more variation than the other two cuts because grain patterns resulting from the growth rings are more obvious.
Quartersawn produces less board feet per log than plainsawing and is therefore more expensive. Quartersawn wood twists and cups less and wears more evenly.
Riftsawn is similar to quartersawn but the cut is made at a slightly different angle.