In this section we will talk about important terms about printing world and typography.

Continuing Printing Terms

Off-print An article or other part of a publication printed with the main run, but produced as a separate item. Also called a separate. Offset To reproduce a book by photographing a previously printed edition.

OK press/sheet Authorization that a job has had all corrections made and is ready for press. Also known as pass for press. One-up A single printing of a single signature or image on a press sheet.

Overexpose/overexposure (2) A fault in platemaking caused when the light source is too close or too bright. Overlaying A method of varying the pressure of a printing plate on a press by adding pieces of paper to the tympan, thereby darkening or lightening the impression.

Overprint To make a second printing or "pass" on a previously printed sheet. Also called surprinting. Overprint To print two or more colors so they overlap, either to produce more colors or to avoid registration problems. The opposite of “knockout.”

Overs A number of copies of a publication printed beyond the number ordered. This is usually deliberate to allow for copies that may be spoiled during finishing or lost or damaged during shipping.

Pages to view A reference to the number of pages that will be visible on one side of a sheet that will be printed on both sides.

Panel The part of a printed page or sheet defined by folds. Panel printing A preprinted area of flat color that will be used as a base for additional printing.

Pass One cycle of a printing surface through a printing press, whether it be a single- or four-color press. Subsequent passes may be required to achieve the desired result, for example, to add more color than was possible on the first pass.

Pass for press A printing job that has had all corrections approved and is thus ready for press. Pass sheet A printed sheet of optimum print quality that is removed from the run so subsequent sheets can be compared with it.

Photomechanical The preparation of printing plates involving photographic techniques. Photoresist A coating selectively applied to a printing plate to protect it from etching chemicals.

Physical dot gain The increase in the size of a halftone dot caused by the spread of ink during printing.

Pick-up A traditional printing term for the reuse of materials from a previously completed print job.
Picking The lifting of fibers on the surface of paper during printing, caused either by sticky ink, poor quality paper, or suction from the blanket cylinder. Also called plucking or pulling.

Plate A book illustration printed separately from the main body and then tipped or bound into the book, although the term is now widely used (erroneously) to describe an illustration printed in a book.

Plate cylinder The cylinder on a printing press onto which the plate is fixed. Platemaking The process of making an image on a printing plate by whatever means, but usually photomechanically transferring it from film.

Plugging An aberration in platemaking in which dot areas become filled in, caused by damage to the plate.

Premake ready The final checking of plates before they are made ready on press.

Preprint An item printed in advance of a publication, later inserted loosely into bound copies. Also called a blow-in.

Press Any machine that transfers (prints) an impression, traditionally from a forme, block, plate, or blanket onto paper or other material. Press gain The mechanical enlargement of halftone dots while printing, as distinct from the "dot gain" of the prepress photographic kind.

Press revise A proof used as the final "pass for press," Also called a machine revise. Press run/run The total number of copies of a print job.

Presswork All of the processes carried out on a printing press, from press make-ready through actual printing to finishing operations.

Prima The first page of a set of printers galley proofs. Print The image etched, or otherwise generated, onto a printing plate. The impression made from a plate, blanket, or so on, onto paper or other material.

Print to paper An instruction to print as many sheets or copies as the paper supplied will permit, without specifying an exact quantity. Also called run of paper.

Printing pressure The force required to transfer an impression between any of the image-bearing surfaces of a printing press, such as plate and paper, plate and blanket, blanket and impression cylinder, impression cylinder and paper.

Printing processes There are four generic printing processes; intaglio (e.g., gravure), planographic (e.g., lithography), relief (e.g., letterpress), and stencil (e.g., screen printing).

Printing unit The unit that houses all the components required to print a single color on a multicolor press (typically the four-unit press that prints the process colors ó cyan, magenta, yellow, and black).

Printmaking The printing of fine art editions by a variety of processes, such as limited edition screenprints and etchings. Process work The general preparation, usually by photomechanical means, of a surface for process printing.

Production press The press used for printing a job, as opposed to the one used for proofing it.It is generally impractical to use the production press for proofing.

Proportionality failure A problem that occurs in the value of an ink hue when the dot size of a halftone tint varies, changing the hue of the ink in relation to a solid ink color.

Pull (sheet) Sheets removed from the press for examination during the print run.

Register/registration The correct positioning of color plates when printed one on top of another, or of the pages on one side of a sheet relative to the other (called "backing up"). When a color or page is incorrectly positioned, it said to be "out-of-register" or "misregistered." As distinct from "fit," which applies to the correct positioning of individual items on a sheet.

Register sheet A sheet used to obtain correct position and register when printing. Resist The coating applied to a printing plate to protect the nonimage areas from acid corrosion.

Retree copy A limited edition book made from "retree" or spare sheets. It is sold "out of series" ó that is, the books are unnumbered and bound as ìovers.î

Rider roller A printing press cylinder that has no motive power of its own, but rotates only when in contact with another cylinder. Roll-to-roll printing Rewinding a continuous printed web onto another roll. Roll-to-sheet A system that cuts sheets from a roll and delivers them into a sheet-fed press.
Roll-up A check of the first printed sheets to emerge from a press while the plate is still being inked.

Roller A cylinder that is used to apply ink to a plate or forme. Also used on small presses to roll the ink out to the correct consistency.

Rotary press Any printing press in which the printing surface is on a rotating cylinder. Paper can be delivered to rotary presses In either sheet or web form.

Rough etch The Initial etching of a descummed copper or zinc plate to reduce the dot size, ultimately giving contrast and depth to the printed image, Also known as "flat etch," although this term also applies to reducing the size of halftone dots on film. Rough etching is followed by "fine etching."

Run of press Printing work carried out at the same time as the main run, rather than supplied to the printer as a preprinted item for later insertion.

Run up The period between the start of a print run (switching the press on) and the point at which a printed sheet of acceptable quality is produced. This period normally generates a certain amount of spoiled sheets.

Run-in sheets The printed (spoil) sheets produced between the start of a print run and the point at which a printed sheet of acceptable quality is produced.

Scribing Making corrections to an image on film or plate by scratching the surface. Set and hold An instruction to the printer to prepare matter in readiness for printing, but not to print.

Setback The distance between the front edge of a printing plate and the start of the image area. Allows for the gripper margin.

Sheet work A particular printing technique that involves printing on both sides of a sheet. Sheet-fed (press) A printing press into which single sheets are fed. Sheetwise (imposition) The technique whereby separate plates are used to print either side of a sheet.

Signature A mark, usually a small capital or a numeral, placed in the tail margin at the beginning of each section of a book, which serves as a guide for finishing and binding. The term also describes the folded sheet itself.

Simplex Printing, photocopying, or duplicating on one side of a sheet of paper only.

Single printing The process of printing a sheet of paper first on one side and then the other. Also called work and turn. Single-color press A printing press capable of handling only one color at a time.

Slur In printing, the "skidding," or smudged, appearance of an image, with blurred or doubled halftone dots or characters. This fault is caused by excessive movement between plate and paper during impression.

SPH abb.: sheets per hour. The speed of a printing press.

Split-duct printing/working A printing technique involving the use of two or more colors on a normal single-color press, achieved by dividing the ink duct into sections for the different inks, and preventing mixing on the forme. Also called split fountain.

Spot color Any color used for printing that has been "custom mixed" for the job, as opposed to one of the four standard process colors.

Start-of-print line The trim line delineated by the trim marks closest to the gripper edge of the printing plate.

Sticking Sheets of printing paper can stick together if they have been guillotined with a blunt knife or stored incorrectly. Sticking after printing is caused by ink remaining wet on the paper, especially hard surface paper.

Stopping out/stop out The process of covering with varnish those parts of the etching plate that do not require additional etching by acid. Also called staging out.

Suction feed A device on a printing press that uses air suction to deliver sheets to the press.
Tall copy A book that has been printed with larger head and foot margins than others in the same print run.

Throughput A unit of time measured as the period elapsing between the start and finish of a particular job, expressed in units per hour or per minute, such as impressions or pages.

Tile/tiling The printing of a document that is larger than the maximum-size paper the printer can accommodate.The document is printed on several pieces of paper, to be assembled by hand to form a whole image.

Title signature An identification, marked with a "B" or "2," on the second sheet of a book indicating that there is a preceding sheet (the "title sheet") that may be unmarked.

Tone compression The inevitable consequence of printing an image, resulting in a reduction of the range of tones from light to dark. Top and tails A traditional printer's description of preliminary and subsidiary matter.

Track The printing line from the front edge of a plate to the back Items imposed in track will all be subject to the same inking adjustments on press.

Transfer paper The substrate that contains an inked impression that will become the printing form for litho printing.

Two-revolution press A cylinder on a printing press that rotates twice for each Impression without reinking. Two-up A method of printing two copies of each page on a single sheet. They are eventually trimmed into separate entities after binding.