Browse words beginning with A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Abrupt Serif	A serif which breaks suddenly from the stem at an angle.
Accent	A diacritical mark near or through a letter indicating a variation in pronunciation. Eg. ç, à, ò, é, Å.
Addressing Resolution	The degree of fineness of position that the computer can specify for an output device.
Adnate Serif	A serif which flows smoothly to or from the stem.
Aliasing	The misrepresentation of high frequencies from the original signal as low frequencies in the sampled result, due to undersampling. Aliasing distorts the letterforms and letter spacing.
Alphabet	A set of abstract symbols employed in a particular writing system.
Analog Letterform	A glyph, drawn or printed, sometimes used as a model for creating a similar digitized shape. Analog letterform designs maybe expressed as smooth curves that are then digitized.
Analphabetic	A typographical character used with the alphabet but lacking a place in the alphabetical order. Examples: the acute accent, the umlaut, the circumflax, and the asterisk.
Anisotropic Scaling	Enlarging or shrinking letters nonlinearly, so that, for example, they become disproportionately less bold and narrower for ther height as they are enlarged. Such transformations can create some of the traditional variations in shape of typefaces at different sizes.
Anisotropy	A property of some output devices that gives different results on the x- and y-axes. In CRT, for example, black features crossed by the scan are narrowed preferentially compared with those running parrallel to the scan.
Anti-aliasing	Removing alias frequencies from the sampled signal. In letterfoms, jaggedness can be minimized during reconstruction by using various grey levels at the edges of stokes.
Antiqua	Another way to describe letters with serifs.
Arc	Segment of a circle or ellipse, sometimes used to describe part of the boundary of a letterform.
Ascender	That part of a lowercase letter that rises above the x-height, as in letters 'b', 'd', 'f', 'h', 'k', 't' and 'l'.
ASCII	The American Standard Code for Information Interchange, a standard character set defined by ANSI, the American National Standards Institure.
Aspect Ratio	The ratio of width to height.
Assimilation	The symmetry propert possessed in varying degrees by a typeface that creates mirror relationships and other similarities of form between letters.
Asymmetry	Aspects of letterforms that depart from mirror images relationships between letter pairs, especially 'b-d' and 'p-q', and within individual letters, such as 'T' in some typefaces.
Axis	The real or imaginary straight line on which a letterform rotates.

B

Back Up	To match the vertical position of lines on the opposite sides of a sheet printed on both sides.
Back Ground	The field on which a letter or graphic appears; the blank paper or screen on which the image is formed.
Ball Terminal	A circular form at the end of the arm in letters such as a, c, f, j, r, and y. Examples of faces which use ball terminals are Bodoni and Clarendon.
Baseline	The line on which letterforms rest. (Round letters like "e" and "o" normally dent it, pointed letters like "v" and "w" normally pierce it, and letters with foot serifs like "h" and "l" usually rest precisely upon it.)
Beak Terminal	A sharp spur, found particularly on the f, and also often on a, c, j, r, and y in many 20th century Romans. (Examples: Perpetua, Pontifex, Ignatius.)
Bézier Splines	A class of third-degree interpolating splines useful for representing letterform shapes.
Bicameral	A bicameral alphabet has two alphabets joined. The Latin alphabet, which you are reading, is an example; it has an uppercase and lowercase. Unicameral alphabets (the Arabic and Hebrew alphabets) only have one case.
Bitmap	An array of intensity values, normally rectangular, used to create an image, as on a screen or on paper. The bits are mapped onto the screen or paper.
Bitmapped Display	An output device that portrays a bitmap image. A raster display is a bitmap display in which the bitmap data are scanned line by line.
Blackletter	A general name for a wide variety of letterforms that stem from the north of Europe. Blackletters are generally tall, narrow, and pointed. In architecture, comparable to the gothic style.
Blackness	The apparent darkness of type as it appears on the page. Blackness depends on the boardness of the parts of the letter (boldness), as well as on the x-height and set.
Bleed	An image that extends to the edge of the paper (after trimming).
Bodoni	A modern typeface with unbracketed serifs, veritcal stress and very high contrast.
Body Size	The height of the face of the type. Originally, this meant the height of the face of the metal block on which each individual letter was cast. In digital type, it is the height of its imaginary equivalent, the rectangle defining the space owned by a given letter (different from the dimension of the letter itself).
Bold	A blacker, heavier variation of a typeface, relative to the roman variation.
Bowl	The generally round or elliptical forms which are the basic body shape of letters such as (uppercase) C, G, O, and (lowercase) b, c, e, o, and p. Similar to the space known as an "eye".
Break	Deciding how much text shall appear on each line or page of a document.
Brightness	The perceived intensity level of light in a visual scene.
Brilliance	Property of a typeface related to its typographic contrast. Also referred to as sparkle.
Bullet	A mark used to set off items in a list, frequently a filled circle.

C

Calligraphic Display	An image-display device that produces images by directly creating lines, arcs, and so on, as opposed to a bitmap display. Also called a stroke display.
Cap Height	The distance from baseline to cap line of an alphabet, which is the approximate height of the uppercase letters. It is often less, but sometimes greater, than the height of the ascending lowercase letters.
Cedilla Ç	The accent, used primarily in French, to soften the letter C.
Cell Text	A monospaced typeface, usually associated with older display devices.
Centered	Text set so as to distribute residual space on the line equally to the right and left.
Character	An abstract symbol, represend within a computer by a numerical code. Also, a symbol in a font or glyph.
Character Set	An ordered set of abstract symbols, used ti represent and exchange information, in which a paricular symbol is represented by its index.
Chase	Rectangular frame used to lock lines of metal type into position in letterpress use.
Chromatic Aberration	An aberration in an optical system that causes light of different colours to be focused in different planes.
Cicero	A unit of measurement used to measure typefaces. It is equal to 12 Didot points, the slightly larger continental European counterpart to the American and British point.
Classical Type Style	Letterforms having vertical axis, adnate serifs, teardrop terminals and moderate aperture. Originated in the 18th century.
Colophon	A description of how a book was produced, normally at the end. Also, a printers' mark or emblem.
Colour: Typography	The overall blackness of a page of text, that is, its average density. By extersion, the blackness of a typeface when set in a block.
Compound Document	A document that contains, in addition to text, graphics, images, or other non-textual components
Condensed	A type design variation with less than normal set; thus a tightly spaced font.
Conic Spline	A spline curve of order two.
Contrast	The ratio of thickness of vertical to horizontal strokes in letterforms.
Counter	The white space enclosed by a letterform, whether wholly enclosed (as in "d" or "o") or partially (as in "c" or "m").
Cubic Splines	A spline curve of order three.
Cursive	Typefaces that resemble handwriting, frequently having joins or the suggestion of joins between letters.

D

DDL	A page-description language developed by Imagen Corporation.
Decode	In reading, to identify letters and words.
DECpage	A document-formatting system developed by Digital Equipment Corporation.
Demand publishing	Creation of printed documents in small runs or even in single copies, as needed.
Demerits	A point system used to rate the quality of a particular arrangement of type, for example, when line breaking in TEX. Lines receive demerits for faults such as being -too loose or tight; paragraphs, for defects such as consecutive hyphenations.
Dentation	The vertical extent on the page of a block of print.
Depth	An ordered set of abstract symbols, used ti represent and exchange information, in which a paricular symbol is represented by its index.
Descender	That portion of a letter that falls below the baseline, as in 'j', 'g', 'q', 'p' and 'y'.
Desktop Publishing	Direct printing of typeset material using small, relatively inexpensive computers and printers under the direct control of the creator of the material.
Diacritical mark	An accent or other three. ancillary mark added to a letter to distinguish it or change its pronunciation.
Diaresis	The accent used to separate the pronunciation of two consecutive vowels, as in coördinating. Similar to the umlaut
Didot point	Unit of type measurement in Europe (except Britain); 1 Didot point = 0. 3 759 mm.
Digital halftoning	The simulation of continuous-tone pictures by the algorithmic arrangement of bivalued picture elements. Also called spatial dithering.
Digital typography	The technology of using computers for the presentation of text, in which the letters themselves are created and positioned under digital control.
Digitisation error	The loss of information in the sampling of a signal. The broader class of errors of which aliasing is an example.
Digitise	To sample an analogue signal and represent the results in a numeric form.
Dingbat	A special symbol not a part of any particular typeface, including arrows, mathematical signs such as square root, and bullets.
Direct manipulation	Style of user interface in which the user modifies or moves parts of the document using a pointing device such as a mouse.
Display. (typography)	Large sizes of type, for use as headlines, titles, and so forth.
Display Type	General term for type set larger than surrounding text as in headings or advertisements. Usually 14-point or larger.
Displayed formulas	Sequences of lines of mathematical notation included within running text.
Dithering	Spatial dithering, the method of creating digital halftones.
Document model	An external myth that presents textual and graphical information as (simulated) paper documents.
Document	Any "printed" image stored in a computer or realised on a piece of paper.
Dots per inch (dpi)	Measure of the resolution of input and output devices.
Double Storey	Seen in the lower case "g" with the closed tail and lower case upright finial "a".
Download	The process of transferring information from one device to another. This transferral is called downloading when the transfer flows from a device of (relatively) more power to one of (relatively) less power. Sending new fonts to your printer so that it learns how to print characters in that font is called downloading.
Draft printing	Printing a test copy of a document before printing it in final form.
Drop Cap	A large initial capital in a paragraph that extends through several lines.
Drop Folio	A folio (page number) dropped to the foot of the page when the folios on other pages are carried at the top. Drop folios are often used on chapter openings.
Dyslexia	A perceptual aberration, one form of which causes confusion of mirror-image letter pairs, especially 'p-q' and 'b-d'.

E

Edge enhancement (image processing)	An image-processing technique that identifies the boundaries of objects and increases their contrast.
Edge enhancement (perception)	The sharpening of edges in an image by the visual system.
Egyptian Type	Letterforms having square serifs and almost uniform thickness of strokes.
Electrographic printer	A printer that uses a direct electrostaticprinting process in which charge is placed directly on the paper and then developed to form an image by the application of toner.
Electronic publishing	Digital typography.
Elite	A typewriter (monospaced) typeface with a pitch of 12 char, acters per inch.
Em Space	A distance equal to the type size - 12 points in a 12 point typeface, 11 points in an 11 point typeface and so on. Also known as a "mutton".
Emdash	A dash the width of the letter "m" used in text to separate a parenthetical note as an alternate to parenthesis.
En space	Half an em. Also known as a "nut".
Endnote	A piece of text associated with the body of a document, like a foot-note but placed at the end of a section or chapter.
Erosion	The thinning of the vertical strokes in letter forms that results from characteristics of the output device.
Expanded	A type design variation with more than normal set. Thus, a loosely spaced or wider than normal font.
Extended	See Expanded.
Extender	Descenders and ascender; i.e., the parts of the letterform that extend below the baseline (p, q) or above it (b, d).
Extensional specification	In a document formatter, the detailed specification of formatting information such as spacing, margins, and font, as opposed to intentional specification, in which the purpose of a passage is described, for example, verse.

F

Facsimile	Electronic representation of images, often entire documents, for transmission over a distance, frequently by a telephone or computer network using digital encoding.
Family	A related set of typefaces.
Fields	The portions of a displayed frame that are scanned alternately in an interlaced refreshing scheme. In broadcast television, the lines in the two fields alternate, and each field contains half of the scan lines.
Figure (perception)	The object seen, as separated in the act of seeing from everything else in the image.
Figure (typography)	A picture or diagram that may be included within the body of a typeset document.
Figures (lining)	Modern numbers, all of which rest on the baseline.
Figures (nonlining)	Old-styled numbers, some of which (3,4,5,7,9) descend below the baseline.
Fill	The graphical operation of reproducing a pattern or colour through, out a bounded area.
Fixation	The stopping of the eye to sample the visual scene. Even during fixations, there are continual small motions of the eye.
Fixed pitch	Monospaced type.
Fleuron	A printer's flower or ornament.
Flicker fusion frequency	The temporal rate of intensity variation of alight or image at which a particular person sees the light as steady. Flicker-fusion frequency varies from person to person, with the degree of modulation of the intensity variation, and with the angle from the centre of the visual field.
Floating object	An illustration, table, or diagram that the document formatter is free to place in various places relative to the running text.
Flower	A printer's decorative symbol. Also called a fleuron.
Flush left	Setting lines of text so that any extra space is on the right, and the text is against the left margin. Also called ragged right.
Flush right	Setting lines of text so that any extra space is on the left, and the text is against the right margin.
Folio	A page number, for example as part of a running head or foot.
Font	A set of characters. In the world of metal type, this means a given alphabet, with all its accessory characters, in a given size. In the world of digital type, it is the character set itself or the digital information encoding it.
Footnote	A floating note associated with a location and reference mark in a text and displayed at the bottom of the page on which the mark occurs.
Foreground	The image or figure, as opposed to the background.
Foundry	Originally, a factory in which metal type is made; now any maker of type.
Fourier transform	The mathematical transformation that allows a function in time or space to be examined in terms of its frequency components.
Fovea	In the eye, the small, central region of the retina that exhibits the greatest sensitivity to detail and colour.

G

Galley	In traditional typesetting, a proof of the running text, tables, or figures, before these parts are combined to form pages.
Gestalt	The perceptual process of separating figure and ground to create an overall visual understanding of an image.
Glyph	(1) The actual shape (bit pattern, outline) of a character image. For example, an italic 'a' and a roman 'a' are two different glyphs representing the same underlying character. In this strict sense, any two images which differ in shape constitute different glyphs. In this usage, ``glyph'' is a synonym for ``character image'', or simply ``image''. (2) A kind of idealized surface form derived from some combination of underlying characters in some specific context, rather than an actual character image. In this broad usage, two images would constitute the same glyph whenever they have essentially the same topology (as in oblique 'a' and roman 'a'), but different glyphs when one is written with a hooked top and the other without (the way one prints an 'a' by hand). In this usage, ``glyph'' is a synonym for ``glyph type,'' where glyph is defined as in sense 1.
Greyscale fonts	Fonts that use variations in intensity at the edges of the letters to suppress the effects of aliasing and thus improve the apparent sharpness and fineness of letterforms.
Greeking	The use of gray bars or "dummy" characters to represent text that is too small to be legible when displayed on the screen. Also, in graphic design, the use of dummy text in a layout so that the design of the document will be emphasized rather than its content.
Grid: engineering	A control structure in a CRT, used to modulate the intensity of the electron beam, and thus the brightness of spots on the phosphor screen.
Grid (typography)	A graphical layout for the design of pages of a book or other document. Variations on pages must match divisions in the grid.
Grotesk	Another way to describe letters without serifs.
Ground (perception)	That part of an image that is seen as the background, rather than the perceived object, called the figure.
Gutenberg: unit of measure	A unit of linear measure equal to 1/7200 inch, or about 1/100 of a point.

H

Hand j	Also H/J. Typesetting abbreviation for hyphenation and justification.
Hairline	The thinnest part of a letter other than the serif. Joins are frequently hairlines. Also, a fine line or rule, the thinnest that can be reproduced in printing.
Half-bitting	The manipulation of the edges of graphic images so as to minimise the effects of aliasing and reconstruction errors. Also called dentation.
Half tone	A method of simulating continuous-tone images with a device that has a small number of output tones, colours, or intensities. The patterns used are called dithers
Heading	Text that introduces sections of text, set off from the text by differences in size, typeface, or position.
Helvetica	A popular sans serif typeface.
Hershey fonts	A public-domain set of typefaces specified as strokes, originally for pen-and-ink plotters, still used in rasterized bitmap form.
Hinting	The process of defining outlines for digital type when resolution is low or sizes are small.
Hints	When a character is described in outline format the outline has unlimited resolution. If you make it ten times as big, it is just as accurate as if it were ten times as small. However, to be of use, we must transfer the character outline to a sheet of paper through a device called a raster image processor (RIP). The RIP builds the image of the character out of lots of little squares called picture elements (pixels). The problem is, a pixel has physical size and can be printed only as either black or white. Look at a sheet of graph paper. Rows and columns of little squares (think: pixels). Draw a large `O' in the middle of the graph paper. Darken in all the squares touched by the O. Do the darkened squares form a letter that looks like the O you drew? This is the problem with low resolution (300 dpi). Which pixels do you turn on and which do you leave off to most accurately reproduce the character? All methods of hinting strive to fit (map) the outline of a character onto the pixel grid and produce the most pleasing/recognizable character no matter how coarse the grid is.
Humanist Type Style	Letterforms which originate from the humanists of the Italian Renaissance.
Hyperacuity	A perceptual phenomenon in which spatial frequencies much higher than usual are detected.
Hypertext	A system proposed by Ted Nelson and others in which a rich structure of interconnections is created and used within on-line electronic documents. e.g. the World Wide Web
Hyphenation	The splitting of a word across lines, as an aid to uniform line breaking.

I

Illusions	Perceptions created in the visual system and brain that differ from the "objective" environment as measured by physical instruments.
Image	Bitmap pictures, often representing real scenes as viewed by a camera, as opposed to text or line graphics.
Image contrast	The ratio of the maximum luminance (intensity) in an image to the minimum luminance.
Imposition	In printing, the arranging of pages on a larger sheet in the correct order and orientation so that when the sheet is folded the pages will appear in order.
Indentation	Insetting a line of text in from the margin, as at the beginning of a paragraph or within an outline, or to set off a quotation.
Inking	The electronic filling of regions on a display.
Inline font specification	A pen path that, in conjunction with a pen shape for marking along the path, specifies a letterform.
Intensity	The luminance of light.
Intensity contrast	See image contrast
Intentional specification	In a document formatter, the functional specification of formatting information without providing details of spacing, margins, font, or the like, as opposed to extensional specification, in which detailed formatting changes are described.
Interchange protocol	A communications convention or standard that describes how information is represented and transmitted from point to point or between (dissimilar) systems.
Interlaced display	A technique used with CRT displays to reduce the data rate at which the display must be refreshed. Two fields, containing alternate lines, are refreshed alternately.
Interleaf	A compound-document editor for workstations, created by Interleaf Corporation.
Interletter space	The horizontal space between individual letterforms within a single word. Interletter space may be adjusted as a function of the letters (see kerning), but its proper value is an integral part of the typeface design.
International Typographic Style	Typographers and designers based their designs on mathematical grids. ITS felt that the san serif type faces were the thing of the future.
Interpolating curves	Parametric curves that are constrained to pass through the control points that specify them.
Interword space	The horizontal space between words on a line. Interword space can be adjusted to achieve justification.
Inverse video	Also, reverse video. Literally, the reversal of black for white and white for black in a bitmap screen image. Incongruously used by computer people to indicate light letters on a dark background, which is the inverse of the historically more common dark letters on a light background. Also, reversal of foreground and background colours.
ISO	International Organization for Standardization, headquartered in Geneva. an agency for international cooperation on industrial and scientific standards.
Italic	A type design that is both slanted and script like cursive. It was originally designed to replicate handwriting.
ITC	International Typeface Corporation, a major vendor of typefaces.

J

Jaggies	The stepped effect of bit-mapped type and graphics caused when square pixels represent diagonal or curved lines.
Joint	The point in common between two adjoining segments of a spline curve.
Justification	Generically, placing lines of text in a particular relationship to one or both margins. As distinct from flush left or flush right, justified text has both the left and right margins even.

K

Kern (n.)	Part of a letter that extends into the space of another.
Kern (v.)	To alter the fit of certain letter combinations so that the limb of one projects over or under the body or limb of another.
Knot	The point where connected curves join.
Knuth, Donald.	Contemporary computer scientist responsible for the TEX formatter and the METAFONT font-production language.

L

Landscape orientation	A layout wider than it is high, whether on screen or paper.
Laser printer	A device similar to an office copier in which the image is created on a photosensitive surface, usually a drum, via a computer-controlled beam of light from a laser.
Lateral inhibition	The basic means by which edges are detected in the retina. Adjacent excitatory and inhibitory regions signal differences in illumination between them.
LCD	Liquid Crystal Display.
Leading	Originally a horizontal strip of soft metal used for vertical spacing between lines of type. Now meaning the vertical distance from the baseline of one line to the baseline of the next.
Left justify	Setting text against the left margin, that is, with unused space all placed at the right. Also called ragged right.
Legibility	The ease with which text is read in ordinary, continuous reading, usually gauged by reading speed and error rate. Also, Readability.
Letterform	A single glyph or letter, such as might be found on a page or screen. Also, the design of such a letter.
Letterpress	Traditional method of relief printing in which individual pieces of type, called sorts, are assembled from cases into lines and blocks of text and printed by inking and direct contact with paper.
Letterspacing	Adjustment of the interletter space within words so as to achieve equal optical space, or sometimes line justification.
Ligature	Two or more letters tied into a single character to perfectly design their spatial interaction.
Linearity: engineering	The degree to which an output device preserves the fixed proportional relationship between addressing and physical dimensions in the output.
Lines per inch (LPI)	The spatial resolution of a device, photographic emulsion, and so forth, expressed as the greatest number of parallel lines per inch that can be resolved. Related only indirectly to dots per inch, which specifies addressing resolution, but not the greatest number of lines that can be sensed or created, which will be at least two times smaller.
Linotype, or LT	A typesetting machine, invented in 1886 by Ottmar Mergenthaler, that casts slugs containing whole lines of type for relief printing.
Liquid crystal display (LCD)	A screen-display technology that uses optically active organic materials to selectively reflect light under electronic control.
Logotype	A typographic trademark or symbol, frequently using distorted letterforms. See advice on Logotype design.
Loose line	A line of print that contains too much blank space (normally between words) compared with adjacent lines and general norms. The nominal interword space used in conventional printing is between a quarter and a third of the point size.
Low-pass filter	A filter that allows low frequencies through, but eliminates high frequency components.
Lowercase	Small letters used in printing that evolved from the Caroline minuscules of approximately 800 A. D. So called because. they are found in the lower part of the printer's type case.
Lucida	A typeface designed by Bigelow & Holmes specifically for digital output. Its low-resolution screen version is known as Pellucida.

M

Macros	Open subroutines, often used to create new commands.
Majuscule	A capital (or other large) letter.
Margin	The blank space to the left, right, above, and below the text on a page. Margins may contain up to 50% of the area of a well-designed book page.
Marginalia	Notes, titles, summaries, or other information in the margins of a document.
Matrix	The copper block onto which the steel die for a letter was stamped. The matrix served as the mold for the face of a type or for a printing plate.
Markup language	A formatting language, that includes textual instructions to the formatter, intermingled with the text to be formatted. For example, HTML & LaTeX.
Mechanical	A camera-ready original, ready for reproduction by off, set printing.
METAFONT	Font production language developed by Donald Knuth.
Metal type	Typesetting technology prior to phototypesetting, a kind of relief printing. See letterpress, linotype and monotype.
Minuscule	Archaic term for a lowercase letter, see also majuscule.
Modeless editor	An editor without states (such as text versus command mode) in the user interface.
Modern Type Style	Letterforms with flat serifs, abrupt and exaggerated strokes, and vertical shading. Originated by Francois Didot in the late 18th century, this style represented a casting away of the decorative baggage of the rococo era.
Monochrome display	Display that presents images in black and white (or some other pair of foreground and background colours). Some monochrome displays are capable of greyscale, that is, gradations of intensity.
Monospaced printing	Printing in which each letter or symbol occupies the same horizontal space.
Monotype	Typesetting machine invented in 1893 by Tolbert Lanston that casts individual letters and assembles them into a block of type, following instructions punched on a paper tape.
Mood of type	The subjective feeling imparted by a typeface, layout, or page of type.
Movable type	What Gutenberg invented-individual letters cast on independent metal bodies, for assembly into blocks for printing.

N

Noise: engineering	That part of a signal, image, and so forth that is independent of the information content of the message.
Nroff	The UNIX batch-oriented document formatter, closely associated with troff, which is used for phototypesetting. It has some programming features such as environments.
Nyquist frequency	The sampling rate at which sufficient information is captured so as to be able to reproduce a signal of a given bandwidth. The Nyquist frequency is exactly twice the highest frequency to be resolved.

O

Object	In programming-language methodology, an object is a unit of a program that contains both code and data. It exhibits a behaviour as a unit, and can be thought of as the simulation of a physical object or system.
Oblique	A slanted type design, following the letter shapes of the roman variation, as opposed to italic, which is also cursive.
ODA	Office Document Architecture, an interchange format for expressing revisable, structured documents, not intended to be human readable.
Office typography	The design and printing of documents for everyday business, scientific, professional, and engineering use. Before desktop publishing, a generally haphazard affair.
Offset printing	Printing method in which an image is developed on one surface and transferred (offset) onto another, and eventually onto the paper.
Oldstyle typeface	A group of typefaces typified by oblique, bracketed serifs.
Optical spacing	Positioning of letters so that they are perceived as having equal spaces between them. Exact geometric spacing does not have this property.
Orphan	A header or the first line of a paragraph that appear as the last line on a page.
Outline font description	Specification of the shapes of letters by defining their boundaries (to be filled with the ink colour).
Overleaf	The other side of a sheet printed on both sides, specifically the page in a book after a right hand page.

P

Page Description Language (PDL)	An executable description that expresses the appearance of a typeset page or series of pages. DDL, Interpress, and PostScript are examples.
Page independence	The property of a page description language that allows the pages within a document to be processed and printed in any order.
Pagination	Laying out the parts of a document into pages.
Parse	To decode and understand, relative to a grammar. Written and spoken language is parsed in reading or listening. Visual images can also be spoken of in these terms.
Pattern recognition	The process of extracting information and structure from a signal or image, by reference to known signals or images.
Pel	A picture element or pixel.
Perception	Seeing and understanding objects by human beings.
Perpetua	Serif typeface created by face, Gill Sans.
Persistence: of a phosphor	The time it takes for the light output of a phosphor to decay to 10% of its original brightness when excited.
Persistence: of vision	The property of the visual system that allows a short flash of light or exposure to an image to be perceived over a longer period of time.
Phosphor	Light-emitting material such as that on the inner surface of a CRT screen, that creates an image when selectively stimulated.
Photo-offset printing	A printing process in which ink adhering to a photographically processed plate is transferred to paper via one or more intermediate surfaces (rollers).
Photocomposition	Typesetting method in which images of letterforms are set by photographically imaging master versions onto film or photographic paper.
Phototypesetting	See Photocomposition.
Pi font	A font of special symbols not in the standard character set.
Pica	A unit of typographic measure, equal to 12 points, or about 1/6 inch. Also, a typewriter (monospaced) typeface with a pitch of 10 characters to the inch and a vertical spacing of six lines per inch (hence the name).
Pixel	A picture element, which is also called a pel. The spot of graphical information displayed at a single location on a screen or other output device, or on paper.
Plasma display	Screen-display technology that uses ionised gas (plasma) to create an image. In some plasma devices, the light emitted by the plasma is used to stimulate a phosphor, which then emits visible light.
Point	A unit of measure used by printers, equal to 1/72 inch. See also Didot point.
Point size	The height of a font, expressed in points.
Polarity asymmetry	The property in an output device that results in changes in shape when image polarity is reversed.
Polygons	A straight-line representation sometimes used to express typefaces in outline form.
Portrait orientation	A vertical-format page or screen, one higher than it is wide.
Postfix	The sequence of specifying instructions and data in which the operation follows the data. For example, adding one and two would be done as 1 2 +. Postfix is also referred to as reverse Polish notation. In the case of a user interface, postfix order requires that an object or objects be selected first. Then the operation to be applied is specified.
PostScript	A page-description language developed by Adobe Systems, Inc.
Power spectrum	The graph of the energy in the component frequencies of a signal.
Prefix	The sequence of specifying instructions and data in which the operation precedes the data. For example, adding one and two would be done as + 1 2. Prefix is also referred to as Polish notation. In the case of a user interface, prefix order requires that the operation be identified, and then the operand or operands.
Proof	A working copy of typeset material printed for the purpose of checking content and format and of making corrections.
Property sheet	A form that describes the formatting characteristics of an object within a WYSIWYG editor/formatter. The sheet is normally hidden, but may be made visible for inspection or modification.
Proportional spacing	Printing in which each letter or symbol occupies an amount of horizontal space that depends upon its design.

Q

Quad: printing

A space equal to the type size. Also, to fill a large blank space in a line with spacing material.

R

Ragged right	Left-justified text that is flush with the left margin and ragged at the right margin. Unused space in each line is at its right.
Random-access display	A display device that draws the image in any specified order. Calligraphic displays are random access. Raster devices are not.
Raster device	A device that produces an image by scanning it as a series of lines.
Readability	The speed at which continuous text can be read. Also Legibility.
Reading for comprehension	Continuous reading, as of a block of text in a book.
Real-time formatting	Presentation of an electronic document in (nearly) printed form while it is being edited.
Recto page	Right-hand page in an opening. Has an odd page number.
Reference mark	A symbol used to refer the reader to a footnote or other information outside of the immediate context of the mark.
Reflection	Light impinging upon a scene that returns back from the scene. Reflections from display screens reduce image quality by reducing contrast. Light reflected from paper (but not the ink) increases image contrast.
Refresh	To redisplay information on a display device. CRT displays, for example, refresh the image many times per second to achieve the appearance of constancy.
Relief printing	A printing process in which a raised surface accepts ink, which is then transferred to paper by direct contact.
Replicating pixels	A method of enlarging an image by mapping each original pixel onto more than one pixel in the enlarged image. Simple transformations like this result in poor-quality enlarged images.
Resolution	The fineness of position and detail produced by an output device or sampled by an input device.
Retina	The photosensitive part of the eye, upon which the lens images the scene being viewed. river. A perceived white rift in a block of type that results from the alignment of interword spaces from line to line. Proper layout and typesetting minimise or eliminate rivers.
Roman	The classical style of type that is upright, as opposed to oblique, is of normal weight as opposed to light or bold, and has graduated thick and thin strokes as opposed to being cursive.
Rule	A thin line, either vertical or horizontal, often used to separate parts of a table or columns of text.
Run-length encoding	A datacompression technique that represents sequences of values by counts of sequential items of the same value, instead of representing the values individually.
Running head	Text such as the title, chapter, or section headings that is repeated on the tops of pages of a book.
Runoff	A number of document-formatting programs of related ancestry that operate in batch mode and use a highly extensional set of formatting commands. Macros within Runoff allow more intentional formatting.

S

Saccade	Motion of the eye between fixations.
Sans serif	A typeface without serifs. See our Typeface Classification Guide.
Saturation	The purity of colour, the degree to which light is pastel versus spectral.
Screen co-ordinates	Specification of a location on a screen in terms of the discrete pixels, as two integers (x,y), as opposed to world or application coordinates, which relate to a simulated co-ordinate system that may be expressed in real numbers and may be completely independent of screen position.
Scribe	A batch-mode document formatter developed by Brian Reid, much more intentional in its specifications that such formatters as Runoff.
Script	A form of typeface based on writing, having generally continuous strokes that connect letters. See our Typeface Classification Guide.
Sector kerning	One method of automatic kerning that calculates the interletter spacing based on stored information about the lateral extent of each letter, assessed in a number of horizontal bands.
Selection	The user-interface action of identifying an object or a portion of text for later operations.
Serif	A small stroke at the end of the main strokes of letterforms. Typefaces with serifs are called serif typefaces and those without, sans serif typefaces.See our Typeface Classification Guide.
Set	The horizontal extent of a given letter. Also, the average width of the letters in a font, normally gauged by the width of a lowercase alphabet.
SGML	Standard Generalised Markup Language, an ISO standard revisable document format.
Shoulder	In letterpress type, the level of metal upon which the relief letter sits on a piece of type. The shoulder provides support in letterpress printing for kerns that project from adjacent pieces.
Sidebearings	The spaces at the left and right of each letter in a font design that allow for the normal spacing of the letters.
Signature printing	Books, magazines, pamphlets, and the like are