Machine Coated - paper or board, which is pigment coated at the end of the paper or board-making machine.

Machine Direction - the direction of a sheet or web of paper corresponding with the direction of the flow of 'stuff' on the paper machine.

Machine Finished (MF) - Any finish obtained on a papermaking machine. It can refer to either the finish on the sheet as it leaves the last drying cylinder of the machine, or the finish given to a sheet by Calendering online.

Machine Glazed (MG) - paper which is dried on the papermaking machine by a very large cylinder with a polished surface. The paper has a smooth and a rough side. MG papers are used for wrapping papers and posters.

Machine Stack - a set of steel rollers at the end of a paper machine between which the paper is passed to give it a smooth surface.

Manilla - originally paper made from pulp produced partly or entirely of manilla hemp, but now mostly composed of softwood kraft pulp. Most commonly used for envelopes.

Matt Paper - coated paper with a dull, smooth finish.

Mechanical Pulp - pulp made by the grinding of steamed or boiled groundwood (without the addition of chemical agents).

Melamine Formaldehyde Resin - a polymer produced by reacting melamine with formaldehyde; wet strengthening agent.

Micrometer - an instrument for measuring small distances accurately, e.g. the thickness of paper.

Microperf - very finely cut perforated edge, designed to simulate the effect of a guillotine cut edge.

Middles - layer of a board situated between the two external layers or between an underliner and the back layer.

Mottled - a variegated effect produced by the mixture of differently dyed fibres or a drip of colour on the wet pulp. When deliberately produced can also be known as 'granite' or 'silurian' effect.