This glossary of printing terms was created by people working in today's printing industry and is brought to you by MirPrint.com. It has been revised and edited and we have rewritten some technical descriptions in every day language to help the non technical person. Any suggestions that you may have on how we can improve this glossary will be carefully considered. Please send your comments and any new definitions to us at MirPrint.com.
An Image Area is any portion of a photographic negative or positive, printing plate, gravure cylinder, offset blanket, stencil, or other image-carrying surface which contains the image(s) to be printed.
Imposition refers to the positioning of pages on a press sheet in such a manner that when the sheet is folded into a signature and cut, the pages will be in the correct sequence. Imposition involves not just the correct positioning of pages on the same side of the sheet, but also the back printing, or the pages printed on the back of the sheet. Back-printed pages can be oriented in a variety of ways; head-to-head imposition involves aligning the back printing so that the top of the page on the front is opposite the top of the page on the reverse; head-to-foot imposition involves aligning the back printing such that the top of the page on the front is opposite the bottom of the page on the reverse; head-to-side imposition involves back printing that is at a right angle to the printing on the front. Coming-and-going imposition is a type of page sequencing in which the recto (or right-hand) pages are in numerical sequence from the front of the book to the back, but the verso (or left-hand) pages are sequenced such that when the book is flipped over, they are then in sequence from the back of the book to the front.
Impression is the pressure necessary to transfer a printed image from a printing plate, blanket, or other image carrier to the paper or other substrate. The term impression is also used to refer to a printed image.
The Impression Cylinder is the part of an offset lithographic printing press which carries the paper or other substrate through the printing unit and beneath the inked press blanket. The impression cylinder also provides a hard backing which allows the blanket to press a strong, solid impression on the paper. (Hence an impression cylinder is also known as a back cylinder or backup roll.) Like the plate cylinder and blanket cylinder, the impression cylinder has a cylinder gap interrupting its circumference, in which is located the gripper, a shaft containing fingers that grasp and hold the incoming sheet of paper and hold it in register under the blanket, before releasing the printed sheet to be sent to the delivery pile.
Imprint means to print other information on a previously printed piece by running it through a press again. It can also be referred to as a Surprint.
Ink Balance refers to the relationship of the densities and dot grains of process inks to each other and the standard density of neutral gray.
This term refers to the ability of paper to prevent ink from penetrating into its surface (in contrast to ink absorbency). Inks that produce the best result by drying via oxidation (as opposed to drying via absorption into the paper) require paper that has sufficiently low porosity. Too much ink holdout, however, can cause ink setoff. Inks achieve greater levels of gloss and better image quality when they dry on the surface of paper, rather than when they are absorbed. However, in some printing processes (such as high-speed web printing for newspapers), it is desirable to obtain rapid ink penetration and drying, a case where increased ink holdout is undesirable.
Ink Jet Printing
Ink Jet Printing refers to a printer that operates by propelling tiny droplets of liquid ink through computer controlled nozzles onto paper. Ink Jet Printers are the most common type of computer printer for the general consumer due to their low cost, high quality of output, capability of printing in vivid color, and ease of use.
The term Insert refers to any pre-printed page or set of pages which are placed into a separately-printed publication. Examples of inserts are advertising supplements, maps, or foldouts. A free-standing insert is a single signature added to a newspaper.
This term refers to a color proof of separations shown on a single piece of proofing paper, instead of an overlay proof.
Interleave refers to the process of inserting sheets of a non-adhering material (called slip sheets) between printed materials as they come off press to prevent ink setoff and blocking.
An ISBN is assigned to each edition and variation (except reprintings) of a book. The ISBN is 13 digits long if assigned after January 1, 2007, and 10 digits long if assigned before 2007. An International Standard Book Number consists of 4 or 5 parts: The parts of a 10-digit ISBN and the corresponding EAN-13 and barcode. Note the different check digits in each. The part of the EAN-13 labeled "EAN" is the Bookland country code.
1. for a 13 digit ISBN, a GS1 prefix: 978 or 979
2. the group identifier, (language-sharing country group)
3. the publisher code,
4. the item number, and
5. a checksum character or check digit.
The ISBN parts may be of different lengths, and usually are separated with hyphens or spaces.