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 or texture pressed into the paper while it is being formed on the papermaking machine. Expressed as M.F. Different finishes are obtained by the number of times paper is passed through the rollers, either dry or wet.

Machinemade paper
Paper made on a very rapid running machine called a "Fourdriner," producing consistent quantities of sheets or rolls.

Magenta
Hue of a subtractive primary and a four-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.

Make-ready
On printing presses, all work done prior to running, e.g., adjusting the feeder, grippers, side guide, hanging plates, adjusting blankets, setting registrations, putting ink in the fountain, balancing ink colors, etc. Also, in letterpress, the building up of the press form so that the heavy and light areas print with the correct impression.

Making or manufacturing order
The specification of a special weight, color or size of paper not available as a standard stocking item off the supplier's shelf, but they will produce it when ordered. Making orders for special sizes, colors and weights of paper are subject to minimums.

Manila
1) A semi-bleached chemical sulphate paper. Not as strong as kraft, but with better printing qualities. 2) Light ecru color commonly associated with manila stock.

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

Match color
A custom-blended ink that matches the specified color in a color system, such as PANTONE MATCHING SYSTEMÒ, ColorcurveTM and ToyoTM. More exacting than four-color process in achieving a specific color and shade.

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

Mechanical die-cutting
Uses sharp steel rules formed into the desired shape and set into a wooden die. Mounted to a letterpress, these rules are designed to cut, score, crease or perforate when pressed against paper and a flat surface. Standard dies are readily available for pocket folders and other common uses.

Mechanical binding
Stacked single sheets of paper that have been hole-punched and secured with a spiral wire or plastic comb.

Mechanical pulp
In papermaking, groundwood pulp produced by mechanically grinding logs or wood chips. Used mainly for newsprint and as an ingredient of base stock for lower grade publication papers.

Mechanical pulping
The process of separating wood fibers for pulp by grinding wood chips mechanically rather than through the use of chemicals.

Merchant
The paper distributor for paper mills and manufacturers.

Metamerism
The tendency of color to appear different under different light sources, such as fluorescent or natural sunlight.

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

Mill
The manufacturing facility where paper is made.

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

Moiré
In four-color process printing, a moiré pattern is created when four screens of colored dots are not properly aligned with each other, thus causing an undesirable, blurry effect. Also, a 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%. 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.

Moldmade paper
Paper made by a slowly rotating machine called a cylinder-mold that simulates the hand-papermaking process. Fibers become more randomly intertwined than in machinemade papers, producing a stronger, more flexible sheet or roll.

Monotone
Printed in one color only.

Mottle
Mottling occurs when a paper stock and ink are incompatible, or when there is too much water on the blanket. The effect is an irregular, blotchy application of ink resulting in a spotty or uneven finish that exhibits high and low spots, or glossy and dull areas on the printed sheet mostly in solid areas.

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