Aqueous Coating A water based coating that seals the printed sheet. Fast drying allows for quick processing of the finished piece.
Basis Weight - Weight per a selected unit of a grade of paper. Grammage or "grams per square meter" is used throughout the world. The U.S. uses many different basis weight designations depending on the type of paper. For text, book or offset, lbs per 500 sheets of 25x38. For writing, bond or ledger, lbs per 500 sheets of 17x22. Cover is lbs per 500 sheets of 20x26 and newsprint, tag or board is lbs per 500 sheets of 24x36. Bond or business weight paper is also referred to as packaged in a ream or 500 sheets of 8.5 x 11.
Bindery - All the manufacturing operations that are performed after printing. They include punching, folding, scoring, foil stamping, die cutting and many other operations.
Bleed -Any image which has been extended beyond the edge of the printed page size. Usually 1/8 to be trimmed off later.
Bulk - Measure of the density or the thickness in relation to the basis weight of a standard sheet of paper. Used in the binding of books and is measured as pages per inch (ppi). Individual sheets are measured using a caliper.
CMYK - The acronym for the process printing colors Cyan, Magenta, Yellow and Black.
Coated Paper - Paper that has been coated with a material to provide printing ink holdout, smoothness and levelness.
Collating - Gathering (assembling sections) or signatures in proper sequence for binding. May be done by hand or by machine.
Color Correction - The adjustment of color values in an image to remove unwanted effects, improve color, characteristics or add color qualities.
Color Sequence or Ink Rotation - The order in which various colors of ink are printed, also the laydown sequence. In multi-color printing, the trapping of each color down depends on the lower tack of each successive color.
Creep - Compensation for the thickness of folded signatures at the spine in a binding job.
Densitometer - Instrument used to measure the optical density of an image or color. Optical density is the intensity of the color or printed image.
Dot gain - An imperfection of printing that causes halftone dots to print larger than they should. This is mainly caused by the absorption of ink by the paper and causes the reproduction to print darker than it should. It also reduces the sharpness of the image.
DPI - Dots per inch, a measurement of output device resolution.
Drawdown - The application of a thin film (by a blade or a bar) of coating or ink to a piece of paper. It is used as a test method for a coating or ink characteristics such as shade, color strength, or coating strength.
Dry Back - The term applied when the density and/or gloss of the freshly printed ink film decreases after drying to a greater extent than expected. It is generally related to overly absorbent paper surface or poor ink-paper choice or match.
Dust - Loose particles of fibers, filler, or coating materials appearing on the edges of a skid, lift or roll of paper. This dust can interfere with the quality of the printing, particularly if on the sheet or web surface.
Four- Color Process - The process of using only 4 ink colors (cyan, magenta, yellow and black) to achieve virtually all colors.
FTP - File Transfer Protocol is a protocol for the web which allows people to exchange files via the internet.
Halftone - A reproduction of a continuous-tone photograph by simulating gradations of tone using dots of varying size, shape or proximity.
Holdout - 1. In paper, the ability to resist surface liquid penetration. 2. In printing, the property of the paper to have low ink absorption, allowing the ink to set on the surface with high gloss; can create set-off with direct printing
Imposition - Positioning pages on a press form so that they will be in the correct numerical sequence after they are folded.
Impression Cylinder - The cylinder against which an impression is made; used to create the pressure required to transfer the image from the blanket to the paper surface.
Match Color - Premixed, semi or fully opaque printing inks used for exact color match, as in corporate logos (i.e.: Coca Cola red, or John Deere green).Used in place of trying to match exact colors by a combination of 3 or 4 process colors. Can also add visual impact and may reduce the process ink costs.
Mottle - Refers to the spotty, uneven appearance of either a printed surface (mostly in solid ink coverage areas), or to a non-uniform distribution of fibers in the formation of a sheet of paper.
Offset Printing - The term used to refer to offset lithography. The printing process where ink is transferred from a plate to a rubber blanket, then to the paper.
Packing - In printing presses, paper or other sheet materials used to underlay the plate and/or blanket (between the cylinder and plate or blanket) to bring the surface of the plate or blanket to the desired height to obtain proper squeeze pressure for printing; can also be adjusted for minor dimensional changes in multipass, multicolor printing jobs, but only around the length of the cylinder (the print length)
Pantone PMS - Premixed ink colors that are specified for spot colors in multicolor jobs.
Pick - Disruption of the surface of the paper caused when the ink is too sticky and the result of this stickiness is that it pulls away bits of the actual paper surface.
Plate - Depending on the printing process, the means by which the image area is separated from the non-image area, the image carrier.
Register - When a design or form is printed on parts or steps, as in multiple colors, it is essential that all parts or inks lay down and match exactly. When they do, they are .in register .
RGB - The acronym for printing in only 3 colors, Red, Green and Blue instead of 4 process colors. Used for computer monitors and color video output.
Screen - The (usually expressed as lines per inch, i.e. 120 lpi,133 lpi, 150 lpi) Used to determine the dots per unit area in developing tonal values in the printed piece. Up to the point of .dot gain ., the higher the screen, the finer the lines per inch, the greater the fineness of detail in the printed piece.
Scumming - A term used to describe the condition resulting when any non-image area of the plate tends to take ink. There can be any number of causes.
Sheet wise - Printing the second side of a sheet of paper by turning if from left to right and hanging a second set of plates.
Show-through - The undesirable condition where the printing of the reverse side can be seen through the sheet under normal lighting.
Signature - A folded sheet of paper, usually a section of a book or magazine, ordinarily obtained be the folding of a single press sheet into 4, 8 or 16 pages. The term .signature . can also be applied to a printed flat sheet that is to be later folded into a multi-page document.
Stitching - A binding method in which the pages of a book or magazine are spread open at the center, then hung on a "saddle" to be stitched or stapled through the fold line at the seam.
Stripping - 1. In preparing lithographic plate making films, the placing of the negatives in the proper place on the page. 2. As a defect in lithographic printing, describes the condition when ink rollers take water preferentially to the ink.
Tack - Refers to the internal "stickiness" of an ink; a measurement of the resistance to splitting of an ink film between two separating surfaces. A certain amount of tack is necessary to offset lithographic printing. High tack does stress the paper surface as the ink film is split from the blanket to the paper surface. If that film splitting stress is sufficient, the paper surface can be disrupted with pick resulting.
Touchplate - A single printing press plate added to accentuate a color, such as adding a second magenta, cyan or spot ink. One such process developed by Dupont is called "Hi Fi" color, and uses up to 4 additional plates to enhance the original 4-color process.
Trap - A slight overlapping that prevents gaps from appearing along the edges of objects or between different colors due to misalignment or movement on the press.
Trapping - The ability to print ink over previously printed ink. Dry trapping is printing wet ink over dry ink. Wet trapping is printing wet ink over previously printed wet ink.
Tumble - Printing the second side of the sheet of paper by turning the sheet top to bottom so that the opposite edge is the lead edge. Can use the same set of plates to print both sides.
Varnish - A thin protective coating applied to a printed piece for protection or appearance.
Work and Turn - Printing the second side of a sheet of paper by turning it over from left to right, using the same edge of the paper as the gripper or lead edge. Using the same set of plates for both sides of the sheet.
Last Update: 11/08/2012