Bleeding

n(1) The diffusion of colorants through a coating from a previously painted substrate due to the action of the vehicle or solvent or both. The action is dependent on the pigments; vehicles, and solvents of the systems. (2) Diffusion of a soluble colored substance from, into and through a coating from beneath, thus producing an undesirable staining or discoloration. Materials which give rise to this effect are tannins or dyes in some types of wood; wood preservatives; bituminous coatings; pigment dyestuffs; and stains. (3) Diffusion of coloring matter from the substrate; also, the discoloration arising from such diffusion. In the case of printing ink, the spreading or running of a pigment color by the action of a solvent such as water or alcohol. (4) Migration to the rubber surface of an oil, wax, or plasticizer as a film or in drops, sometimes called sweating. Also a term applied to organic pigment colors if they migrate into an adjacent stock of a different color, or when they are...