BACK : Opposite side of the face of the board.
FACE : Visible side of the board.
MULTI-LAYER : Pieces or wood panels made with several layers of veneers or lumber glued on top of each other. More often than not, these woods are made with cross layers but can also use LVL technique (Length versus Length).
SAND : To flatten wood surface.
SINGULARITY : It can be a small knot, some sapwood or any other sound character being part of the nature of the wood. Or, a slight trace of sanding can be found on the back.
SOLID WOOD : Wood being 5mm thick or more.
SQUARE-EDGED LUMBER : piece of solid wood with 4 sharp edges.
VENEER : Precious or semi-precious wood being less than 5mm, generally used to cover a surface made of less precious wood. Can also be used as core in case of multi-layer sheets.