Glossary of printing and graphical terms

CMYK
CMYK (short for cyan, magenta, yellow, and key (black), and often referred to as process color or four color) is a subtractive color model, used in color printing, also used to describe the printing process itself. Though it varies by print house, press operator, press manufacturer and press run, ink is typically applied in the order of the acronym.
The CMYK model works by partially or entirely masking certain colors on the typically white background (that is, absorbing particular wavelengths of light). Such a model is called subtractive because inks “subtract” brightness from white.

RGB
The RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue. Not used in printing works.

Pantone colors (PMS, spot-, specially mixed colors)
Unlike CMYK, it is a system of pre-defined, pre-mixed unique colors according to Pantone Matching System.

L*a*b*
L*a*b - unlike RGB and CMYK - is a device-independent color profile.

Color mixing, color processes
Additive Color Process - A means of producing a color reproduction or image by combinations of blue, green, and red colored lights, such as in color television systems.
Subtractive Color Process - A means of producing a color reproduction or image by combinations of yellow, magenta, and cyan colorants on a white substrate.

Color management
Processes needed for true-color printing.

ICC profile
ICC (International Color Consortium) Profiles describe the color attributes of a particular device or viewing requirement by defining a mapping between the source or target color space and a profile connection space (PCS). This PCS is either L*a*b* or CIE XYZ color space. Mappings may be done using tables, to which interpolation is applied, or through a series of parameters for transformations.

DPI (dot per inch)
DPI is considered as "dots per square inch," a measure of output resolution in relationship to printers, imagesetters and monitors. Monitor - or on-screen - dpi is usually 72, in printing work we use 300 dpi.

JPEG ('Joint Photographic Experts Group')
In computing, JPEG is a commonly used method of compression for photographic images. The name JPEG stands for Joint Photographic Experts Group, the name of the committee that created the standard.The JPEG standard specifies both the codec, which defines how an image is compressed into a stream of bytes and decompressed back into an image, and the file format used to contain that stream. The compression method is usually lossy compression, meaning that some visual quality is lost in the process and cannot be restored, although there are variations on the standard baseline JPEG that are lossless. 

LPI (lines per inch)
Lines per inch (LPI) is a measurement of printing resolution in systems that use a halftone screen. Specifically, it is a measure of how close together the lines in a halftone grid are. Higher LPI indicates greater detail and sharpness. FlipSign plates' resolution is given in LPI.

PPD (PostScript Printer Description)
PostScript Printer Description (PPD) files are created by vendors to describe the entire set of features and capabilities available for their PostScript printers.

Bleed(ing) color
Printing color that extends to the edge of a sheet or page after trimming. When designing these prints, edge-colors must be extended over sheet edges by 3 mm at least at every sides, in order the paper's white not to outcome at the edges after trimming.

ISBN (International Standard Book Number)
A number assigned to a published work and usually found either on the title page or the back of the title page. Considered an International Standard Book Number.

ISSN (International Standard Serial number)
An International Standard Serial Number (ISSN) is a unique eight-digit number used to identify a print or electronic periodical publication. Consists of ISSN and two 4-character numbers (e.g. ISSN 1214-3442).

Electronic document
An electronic document is any electronic media content (other than computer programs or system files) that are intended to be used in their electronic form, and are stored on floppy disks, CD-ROMS etc.

Braille-writing
The braille system, devised in 1821 by Frenchman Louis Braille, is a method that is widely used by blind people to read and write. Each braille character or cell is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. 

Indentation
Using pre-defined measures to place text farther to the right to separate it from surrounding text - usually at the beginning of paragraphs.

Prelim(-inary page)s
Preliminary pages - The first pages of the book that appear before the text begins. Also known as preliminary leaves or prelims.

Copyright page
The page is usually located on the verso of the title page, or on the fourth page of prelims and contains the publisher's information, copyright notices, disclaimers, and the Library of Congress Information. This page is the very important in determining edition and printings for collectors of modern first editions.

CtP technology
Computer to plate (CTP) is an imaging technology used in modern printing processes. In this technology, an image created in a Desktop Publishing (DTP) application is output directly to a printing plate.CTP has several advantages over conventional platemaking. In CTP, one entire generation (transfer of film image to the printing plate) is removed from the printing process, increasing sharpness and detail. Plates are produced in less time and more consistently, eliminating the possibility of misregistration. CTP ensures better registration, and image-to-edge repeatability than traditional methods.
CTP is registered (held in precise position) in the CTP machine itself, and does not rely on a separately-aligned pin grid, as is the case with film. Defects due to dust, scratches or other artifacts are minimized.
CTP systems can significantly increase print shop productivity. The fastest platesetters can output more then 300 12-inch plates per hour, punched and ready to hang on the press.
CTP decreases dot gain slightly by eliminating the increase in halftone dot size which can occur in the film-to-plate exposure process when negative film is used. (Mainly US)
CTP increases dot gain slightly by eliminating the decrease in halftone dot size which can occur in the film-to-plate exposure process when positive film is used. (Mainly Europe)
Small portrait presses that typically create 1 or 2 color output can use anything from a standard laser printer, for low quality/low volume, up to a higher-end dedicated platesetter for higher quality and volume.

Small caps
Kapitälchen - in typography, small caps (short for small capitals) are uppercase (capital) characters that are printed in a smaller size than normal uppercase characters of the same font. Typically, the height of a small capital will be one ex, the same height as most lowercase characters in the font; classically, small caps were very slightly taller than x-height.[citation needed] Well-designed small capitals are not simply scaled-down versions of normal capitals; they normally retain the same stroke weight as other letters, and a wider aspect ratio to facilitate readability.

Colophon
An identifying inscription or emblem from the printer or publisher appearing at the end of a book. Also the emblem at the bottom of the spine on both the book and dust-wrapper as well as a logo on the title or copyright page. Early books often had a colophon instead of a title page imprint and modern private press or other examples of fine printing often use a colophon. A colophon is generally considered to be a formality by the big publishers and is not often used.

l.c.
lower case

cap.
capitals, majuscules

it.
italic

Imagesetting
Using of a digital output device (imagesetter) for creating films for offset-litho printing. Digital files are output in a similar way to normal laser printing, but printed as separations (4 layers of CMYK colors) for high-quality reproduction.
The 4 produced films are realized onto printing plates by a photochemical way.

Halftone / printing grid
Halftone - Image in which the range of tones consists of dots of varying area but of uniform density. Creates the illusion of continuous tone when seen at a distance. The normal imaging technique for reproducing tones by lithography, letterpress, flexography, and screen printing. 

Printable area
The area on a sheet of paper where the printer has the ability to print. Printing heads are within, page numbers are outside this area. 

Color separation
The process of making film intermediates from the color original to record the red-, green-, and blue-light reflectances. These films are used to prepare the cyan, magenta, and yellow printing plates. A black separation is also made.

Cut / Finished Size
The size of products after production is completed, as compared to flat size. Also called trimmed size. 

Blank Leaves
Intentionally left blank pages in a book. Also known as blank pages or printer's blanks.