Stain – A discoloration in wood caused by a chemicals, fungus, or minerals. A dye or pigment used to discolor wood.
Blue Stain – A bluish discoloration of the sapwood caused by the growth of certain dark-colored fungi on the surface and in the interior of the wood.
Brown Stain – A rich brown to deep chocolate-brown discoloration of the sapwood of some pines caused by a fungus that acts much like the blue-stain fungi.
Chemical Brown Stain – A chemical discoloration of wood, which sometimes occurs during the air drying or kiln drying of several species, apparently caused by the concentration and modifications of extractives.
Sap Stain – A discoloration of the sapwood caused by the growth of certain fungi on the surface and in the interior of the wood; made possible by the same conditions that favor the growth of other fungi.
Sticker Stain – A brown or blue stain that develops in seasoning lumber where is has been in contact with the stickers.