Glossary of Printing Terms
For many people, printing terms are unfamiliar—some even date back to the 15th century when Johannes Gutenberg invented the first printing press. While we do our best to convert “Printerese” into everyday English, this guide can be helpful when we inadvertently slip the occasional “densitometer” or “saddle stitch” into our conversation.
.ai: An Adobe Illustrator file.
Accordion Fold: Bindery term, two or more parallel folds that open like an accordion. Against the grain: At right angles to direction of paper grain.
Basis weight: Weight in pounds of a ream of paper cut to the basic size for its grade.
BRM: Business Reply Mail
Bind: To fasten sheets or signatures with wire, thread, glue. or by other means.
Bindery: The finishing department of a print shop or firm specializing in finishing printed products.
Bitmap: a one-bit TIFF typically used for line art.
Bleed: Printing that goes to the edge of the sheet after trimming. Blind embossing: An image pressed into a sheet without ink or foil.
Brightness: The brilliance or reflectance of paper.
Caliper: Paper thickness in thousandths of an inch.
CMYK: (Cyan Yellow Magenta Black) the colors that the printing process uses to produce full color.
Cast coated: Coated paper with a high gloss reflective finish.
Coated paper: A clay-coated printing paper with a smooth finish.
Collate: A finishing term for gathering paper in a precise order.
Color bars: colors that run across the top of a press sheet to allow measurement of ink density. Used to ensure consistancy in color.
Color correction: Methods of improving color separations.
Color-matching system: A system of formulated ink colors used for communicating color, usually Pantone Matching System (PMS).
Color separations: The process of preparing artwork, photographs, transparencies, or computer-generated art for printing by separating into the four primary printing colors.
Continuous-tone copy: Illustrations, photographs, or computer files that contain gradient tones from black to white or light to dark.
Cover paper: A heavy printing paper used to cover books, make presentation folders, etc.
Creep: The process during imposition that keeps the middle pages of a saddle-stitched book in the same position relative to the outer pages.
Crop: To cut off parts of a picture or image.
Crop marks: Printed lines showing where to trim a printed sheet.
Crossover: Printing across the gutter or from one page to the facing page of a publication. CTP: see Direct to Plate
Cyan: Process blue, one of the four colors in process color.
Densitometer: A quality-control device to measure the density of printing ink. Density: The degree of color or darkness of an image or photograph.
Die: Metal rule or imaged block used to cut or place an image on paper in the finishing process.
Die cutting: Cutting images in or out of paper.
Digital Proof: A proof made directly from the digital art file.
Direct to Plate or CTP: The art file goes directly from the computer to plate with no film in between.
Dot: An element of halftones. Using a loupe you can see that printed pictures are made of many dots.
Dot gain or spread: A term used to explain the difference in size between the dot on the plate and on the press.
Double burn: Exposing a plate to multiple images.
Dummy: A rough layout of a printed piece showing position and finished size. Duotone: A halftone picture made up of two printed colors.
EPS (Encapsulated Post Script): usually from a draw program like Illustrator. Emboss: Pressing an image into paper so that it will create a raised relief. Emulsion: Light-sensitive coating found on printing plates and film.
Flood: To cover a printed page with ink, varnish, or plastic coating.
Foil: A metallic or pigmented coating on plastic sheets or rolls used in foil stamping and foil embossing.
Foil Emboss: Foil stamping and embossing an image on paper with a die. Foil Stamping: Using a die to place a metallic or pigmented image on paper.
Four-color process: The process of combining four basic colors to create a printed color picture; or colors composed from the basic four colors.
FSC Certified: The Forest Stwardship Council (FSC) is an international organization
that promotes environmentally appropriate, socially beneficial, and economically viable management of the world’s forests. Mustard Press’ certificate number is SCS-COC-002611. www.fsc.org
Gang: Getting the most out of a printing press by using the maximum sheet size to print multiple images or jobs on the same sheet. A way to save money.
Ghosting: A faint printed image that appears on a printed sheet where it was not intended. More often than not, this problem is a function of graphical design. It is hard to tell when or where ghosting will occur. Sometimes you can see the problem developing immediately after printing the sheet, other times the problem occurs while drying. However the problem occurs, it is costly to fix, if it can be fixed. Occasionally, it can be eliminated by changing the color sequence, the inks, the paper, changing to a press with a drier, printing the problem area in a separate pass through the press, or changing the racking (reducing the number of sheets on the drying racks). Since it is a function of graphical design, the buyer pays for the increased cost.
Gloss: A shiny look reflecting light.
Grain: The direction in which the paper fibers lie.
Grippers: The metal fingers on a printing press that hold the paper as it passes through the press, 3/8”.
Halftone: Converting a continuous tone to dots for printing.
Hickey: Reoccurring unplanned spots that appear in the printed image from dust, lint, dried ink.
Highlight: The lightest areas in a picture or halftone.
Image Area: Portion of paper on which ink can appear.
Imposition: Positioning printed pages so they will fold in the proper order. Imprint: Adding copy to a previously printed page.
Indicia: Postal information place on a printed product.
JPEG or JPG: (Joint Photographic Experts Group) compression technique for colour images and photographs that balances compression against loss of detail in the image. The greater the compression, the more information is lost
Kiss cut: To cut the top layer of a pressure-sensitive sheet and not the backing.
Laminate: To cover with film, to bond or glue one surface to another.
Line copy: High-contrast copy not requiring a halftone.
Lines per inch: The number of rows of dots per inch in a halftone.
Links: The photos and art placed in your document. (Typically an EPS or TIFF).
Loupe: A magnifying glass used to review a printed image, plate, and position film.
Magenta: Process red, one of the four colors in process color.
Makeready: All the activities required to prepare a press for printing.
Matte finish: Dull paper or ink finish.
Micrometer: Instrument used to measure the thickness of different papers.
Middle tones: The tones in a photograph that are approximately half as dark as the shadow area.
Moire: Occurs when screen angles are wrong, causing odd patterns in photographs.
Offsetting: An intermediate surface used to transfer ink. Also, an unpleasant happening when the images of freshly-printed sheets transfer images to each other.
Offset paper: Term for uncoated book paper.
Opacity: The amount of show-through on a printed sheet. The more opacity or the thicker the paper, the less show-through. (The thicker/heavier the paper, the higher the cost.)
Outline: Removing the background of a picture or silhouetting an image in a picture. Also converting a font to art.
Overlay: The transparent cover sheet on artwork often used for instructions.
Over-run or Overs: Copies printed in excess of the specified quantity. (Printing trade terms allow for +/-10 % to represent a completed order.) see under-run.
Pantone: The color management company of record. The Pantone Matching System provides a universal language of color that enables color-critical decisions through every stage of the workflow for brands and manufacturers. More than 10 million designers and producers around the world rely on Pantone products and services to help define, communicate, and control color from inspiration to realization.
PDF (Portable Document File): These must be written correctly for the printing process. If you have questions, ask Kirk.
.psd: Photo Shop Document
Page count: Total number of pages in a book including blanks.
Perfect bind: A type of binding that glues the edge of sheets to a cover like a telephone book, Microsoft software manual, or Country Living Magazine.
Perfecting press: A sheet-fed printing press that prints both sides of a sheet in one pass.
Pica: Unit of measure in typesetting. One pica = 1/6 inch.
Picking: Printer’s nightmare that occurs as the surface of a sheet lifts off during printing. Generally a paper manufacture’s quality control problem.
PMS: The abbreviated name of the Pantone Matching System.
Point: For paper, a unit of thickness equaling 1/1000 inch. For typesetting, a unit of height equaling 1/72 inch.
PostScript: The computer language most recognized by printing devices.
PreMailer: A brochure that has a glued, perforated, and dry-gummed envelope incorporated to allow a person to send back information or money.
Pressure-Sensitive Paper: Paper material with self-sticking adhesive covered by a backing sheet.
Process colors: Cyan (process blue), magenta (process red), yellow (process yellow), black (process black).
RGB: (Red Green Blue) The colors that most monitors use to display full color.
Ream: Five hundred sheets of paper.
Register: Used to position print in the proper position in relation to the edge of the sheet and to other printing on the same sheet.
Register marks: Cross-hair lines or marks on film, plates, and paper that guide strippers, platemakers, pressmen, and bindery personnel in processing a print order from start to finish.
Reverse: The opposite of what you see. Printing the background of an image. For example; type your name on a piece of paper. The reverse of this would be a black piece of paper with a white name.
Rip files: A method of making printable files from PostScript files created by desktop publishing.
Saddle stitch: Binding a booklet or magazine with staples in the seam where it folds.
Scanner: Device used to make color separations, halftones, duotones, and tri tones. Also a device used to scan art, pictures, or drawings in desktop publishing.
Score: A crease put on paper to help it fold better.
Screen angles: Frequently, a desktop publisher’s nightmare. The angles at which halftone, duotones, tri tones, and color separation printing films are placed to make them look right.
Self-cover: Using the same paper as the text for the cover.
Shadow: The darkest areas of a photograph.
Sheetwise: A press sheet where the front is on one plate and the back is on another.
Short Panel: The last panel of a brochure is 1/16 shorter, allowing it to fold correctly.
Show-through: Printing on one side of a sheet that can be seen on the other side of the sheet.
Signature: A sheet of printed pages which, when folded, becomes a part of a book or publication.
Skid: A pallet used for a pile of cut sheets.
Specifications: A precise description of a print order.
Spine: The binding edge of a book or publication.
Spot Varnish: Varnish used to highlight a specific part of the printed sheet.
Staccato or Stocastic: A random dot pattern that allows a smoother look than the traditional rosette pattern.
Stet: A proof mark meaning “let the original copy stand”.
Stock: The material to be printed.
Substance Weight: A term of basis weight used when referring to bond papers.
Substrate: Any surface on which printing is done.
TIFF: (Tagged Image File Format) Best file format saved from PhotoShop.
Text paper: Grades of uncoated paper with textured surfaces.
Tints: A shade of a single color or combined colors.
Transparency: A positive photographic slide or film that allows light to pass through.
Transparent ink: A printing ink that does not conceal the color under it.
Trapping: The ability to print one ink over the other.
Trim marks: Similar to crop marks or register marks. These marks show where to trim the printed sheet.
Trim size: The final size of one printed image after the last trim is made.
Under-run: Production of fewer copies than ordered. See over-run.
Up: Printing two or three up means printing multiple copies of the same image on the same sheet.
UV coating: Liquid laminate bonded and cured with ultraviolet light. Environmentally friendly.
Varnish: A clear liquid applied to printed surfaces for looks and protection. (UV coating looks better.)
Verso: The left hand page of an open book.
Vignette halftone: A halftone with a background that gradually fades to white.
Watermark: A distinctive design created in paper at the time of manufacture that can be easily seen by holding the paper up to a light.
Web press: The name of a type of presses that print from rolls of paper.
Wire O: A bindery trade name for mechanical binding using double loops of wire through a hole.
Wire-O Binding: A method of wire binding books along the binding edge that will allow the book to lay flat using double loops. See Wire O.
With The Grain: Folding or feeding paper into the press or folder parallel to the grain of the paper.
Work and Tumble: Printing one side of a sheet and turning it over from the gripper to the tail to print the second side using the same side guide and plate for the second side.
Work and Turn: Printing one side of a sheet and turning it over from left to right using the same side guides and plate for the second side.
Wove paper: A paper having a uniform unlined surface with a smooth finish.