MACHINE CLOTHING
Fabrics of various types employed on the paper machine to carry the web and perform other functions. It includes the machine wire and wet and dry felts that may be composed of natural or synthetic materials.

MACHINE COATING
See On-Machine Coating.

MACHINE DECKLE
The overall width of the wet web as it leaves the forming zone of the papermaking machine. Note: often used incorrectly to indicate the width of the web at the dry end of the machine.

MACHINE DIRECTION
The direction the wire mesh on a papermaking machine is traveling. Over 50% of the fibers position themselves with their lengths parallel to this direction.

MACHINE FILL OR DECKLE FILL
The width of the papermaking machine taken up by a making of paper. For reasons of economy, it should approach so far as possible the maximum trimmed width of the machine.

MACHINE FINISHED PAPER (MF)
Paper that has been made reasonably smooth by means of calender stacks at the end of the papermaking machine.

MACHINE-GLAZED PAPER (MG)
Paper that has had one side made smooth and glossy by drying in contact with a large, heated, polished metal cylinder that forms part of the drying section of the machine. The other side of the paper remains relatively rough.

MACHINE WIRE
The fabric used for converting the dilute stock into a formed sheet by permitting drainage of water and retention of the other elements of the stock. It may consist of a woven wire cloth or a plastics or similar fabric that contains a suitable pattern of perforations.

MANIFOLD
See Airmail Paper.

MAXIMUM TRIMMED WIDTH
The greatest width of usable paper it is possible to make on a given papermaking machine, i.e., the full width less the necessary trim to give clean edges. It is not possible to specify sizes that, in aggregate, exceed this width.

MECHANICAL PAPER
Paper, the furnish of which contains a substantial proportion of mechanical wood pulp.

MECHANICAL PRINTINGS
Printing papers made chiefly from pulp produced by the groundwood method. By this method of pulp production the wood is mechanically ground with water to separate the fibers and produce pulp. This grade may be coated on or off the machine, machine or supercalendered.

MECHANICAL WOODPULP (GROUNDWOOD)
Pulp produced from wood solely by mechanical means such as grinding or refining.

MICRO-CREPING
A process for compacting the paper web in the machine direction and imparting a high degree of stretchability by passing the web between a roll and, for example, an endless rubber blanket. The blanket is extended immediately before the point of contact with the web and allowed to return to its normal state during the passage of the web through the space between the roll and the rubber blanket. A typical example of micro-creping is the Clupak process.

MICR PAPER
Magnetic Ink Character Recognition Paper. Usually a high-quality bond paper with good surface characteristics and dimensional stability for printing with magnetic inks for computer sorting.

MIDDLE (OF BOARD)
Furnish layer of a board situated between the two external furnish layers, or between the underliners, or between an underliner and an external furnish layer.

MILLBOARD
A thick, dense, homogeneous board for book production, made generally from wastepaper, on a special board-making machine, one sheet at a time. Used in binding case bound books, ledgers, etc., as binders' boards.

MIS-REGISTER
The appearance of a printed image out of its correct position.

MOLD-MADE
Originally, paper made by hand by the traditional method of paper molds, usually from rag pulp. Today, mold-made papers are high-quality grades made on a cylinder mold machine, as opposed to a Fourdrinier or other type of machine, and may be made with or without deckle edges.

MULTIPLY BOARD MACHINE
A machine in which a number of plies of paper can be combined together in the wet state to produce thick cardboard.