M weight: The actual weight of 1000 sheets of any given size of paper.
Machine Coated: Paper that has had a coating applied to either one or two of its sides during the papermaking process.
Machine Direction: An alternate term for grain direction.
Machine Finish: A paper finish that results from the interaction of the paper with the Fourdrinier process as opposed to post machine embossing. Reference, Fourdrinier
Magnetic Black: Black pigments containing black iron oxides, used for magnetic ink character recognition.
Make Rready: Process of adjusting final plate on the press to fine tune or modify plate surface.
Margin: Imprinted space around edge of page.
Mark-up: To write up instructions, as on a dummy.
Mask (1): The blocking out of a portion of the printing plate during the exposure process.
Mask (2): A photo negative or positive used in the color separation process to color correct. Reference, PRINTING, mask.
Match Print: Photographic proof made from all color flats and form composite proof showing color quality as well as accuracy, layout, and imposition before plates are made.
Matte Finish: A coated paper finish that goes through minimal calendaring. Reference, calendaring.
Measure: The width of type as measured in picas. Reference, picas.
Mechanical: A term used to describe finished artwork that is camera ready for reproduction, including all type, photos, illustrations etc.
Metropolitan Service Area: A group of ZIP codes usually in close proximity defining a large metropolitan area (e.g. New York City or Los Angeles).
Midtone Dot: Commonly taken as the area between highlight and shadow area of a subject's face in halftone image.
Moire: An undesirable halftone pattern produced by the incorrect angles of overprinting halftone screens.
Molleton: A cotton fabric used on the dampening rollers of a printing press.
Molybdate Orange: An ink pigment made from precipitating lead molybdate, lead sulfate and lead chromate.
Mottle: A term used to describe spotty or uneven ink absorption.
Mull: Coarse muslin glue placed on the back of book or pads for strengthening.
Mullen Testing: A specific test of tensile paper strength; an important factor if web presses are used for printing.