Bluestain and brownstain are seldom the cause of complaints after applying Weather-Bos™, however this is completely dependent upon proper preparation and application procedures. To receive long term protection and pleasing aesthetics requires using adequate quantity of Weather-Bos™;. Bluestain is biological in origin and the fungi feed primarily on starch stored in the ray cells of the sapwood. The color of this stain is usually blue and is caused by pigment in the mold strands or hyphae. Most common to pine, these stains may occur prior to drying and can also develop in once dry woods. They often develop in the interior of a bright board and will be exposed by planing or resawing. Brownstain is a light brown biochemical stain, which appears during drying and is a result of prior enzyme activity during the storage or processing of logs and lumber. Removal of bluestain and brownstain is not practical since both types occur at depth in the wood, rather than being confined just to the surface.