A printing defect characterized by a spotty, non-uniform appearance in solid printed areas. Different print characteristics have different types of mottle; there is a density mottle, a gloss mottle, or a color mottle, depending on what aspect is being affected. All forms of mottle are typically the result of non-uniform ink absorbency across the surface of the paper. A mottled appearance is also called galvanized. A complex type of mottle is called back trap mottle. (See ["Back Trap Mottle [BTM]"].)
A type of mottle characteristic of calendered papers is known as coating mottle.
In binding and finishing, the term mottle is used to describe a type of edge staining, a decorative treatment of the trimmed edges of a book. See Edge Staining and Sprinkled Edges.