M

M - Symbol in the paper industry designating 1,000. Usually used to designate 1,000 sheets or two reams of fine paper.

m weight - is the actual weight in pounds of 1000 sheets of paper regardless of the basic size or paper grade.

machine direction - Establishes the grain direction, which is always parallel with the travel of the paper over the wire.

machine dried - Process of drying paper on the paper machine as opposed to air drying the paper after removal from the machine.

machine finish - Finish that is obtained while the paper is on the paper machine. Expressed as M.F. Different finishes are obtained by the number of times paper is passed through the rollers, either dry or wet.

magenta - Hue of a subtractive primary and a 4-color process ink. It reflects or transmits blue and red light and absorbs green light.

magenta screen - A dyed contact screen, used for making halftones.

makeready - In printing presses, all work done prior to running; adjusting the feeder, grippers, side guide, putting ink in the fountain, etc. Also, in letterpress, the building up of the press form, so that the heavy and light areas print with the correct impression.

making order - A quantity of paper manufactured to custom specifications such as special weights, colors, or sizes usually not available as standard stocking items. Paper mills offering this service establish minimum order requirements.

margins - The unprinted area around the edges of a page. The margins as designated in book specifications refer to the remaining margins after the book has been trimmed.

mask - In color separation photography, an intermediate photographic negative or positive used in color correction. In offset lithography, opaque material used to protect open or selected areas of a printing plate during exposure.

mechanical (paste-up) - Camera-ready assembly of all type and design elements together with instructions and ready for the plate-maker.

mechanical pulp - In papermaking, groundwood pulp produced by mechanically grinding logs or wood chips. It is used mainly for newsprint and as an ingredient of base stock for a lower grade publication papers.

metallic inks - Ink containing metal substances, used to produce special printed output.

middle tones - The tonal range between highlights and shadows of a photograph or reproduction.

mill brand - Paper which is brand-named by the manufacturer as opposed to the merchant house, which is known as a "private brand".

moiré - Geometric pattern caused when two screened images are superimposed at certain angles. Occurs when making a halftone from a halftone image.

moisture content - Refers to the amount of moisture found in a sheet of paper. Average amount ranges from 5 to 8 percent. This figure varies from sheet to sheet since paper will emit or absorb moisture according to the condition of the surrounding atmosphere. Moisture loss is realized in the form of shrinkage, which begins at the edges of the paper and moves across the grain causing the sheet to tighten and curl.

monochromatic - Composed of tints and shades of a single color.

monotone - Printed in one color only.

montage - In artwork, several photographs combined to form a composite illustration.

mottled finish - Finish, which exhibits high and low spots, or glossy and dull areas on the printed sheet.

mullen tester - Device that measures the bursting strength of paper. Sometimes referred to as the pop test or pop tester.