A Glossary of DTP, Printing and Typographical Terms

• Accent - A small symbol superimposed on a letter, normally denoting the way in which it should be pronounced. In English, accents are only used in words of foreign origin such as cafe, naive and Noel. In most European languages accented characters are quite common. Acorn outline fonts include a wide range of accented characters allowing most European languages to be reproduced correctly.
  
• Anti-aliasing - Use of intermediate shades on the screen to overcome the screen's lack of resolution. When fonts are reproduced on the screen, anti-aliasing helps to smooth out the "steps" that would otherwise appear in diagonal strokes (such as the main strokes in the letter "A").
  
• ASCII - American Standard Code for Information Interchange. A code in which letters, numerals, punctuation marks and other symbols are represented by numbers. All computers use ASCII although considerable variations do exist. The original ASCII code was a 7-bit code involving numbers from 0 to 127. Codes 0 to 31 are "control" codes which control cursor movement and other effects. Codes 32 to 126 are printable characters. Code 127 represents "Delete". In the Acorn outline fonts, codes 128 to 255 are also allocated to printable characters which greatly extends the range of characters available.
  
• Bezier curves - The system used in !Draw's path objects for storing data concerning curved lines. Each line is defined by the coordinates of its start and finish and the coordinates of two "control points", one relating to each end of the line.
  
• Bit - The direction of the control point from the line end indicates the direction of the curve at that end of the line. The distance of the control point from the end of the line is inversely proportional to the rate at which the curve diverges from its original direction. Short for "binary digit". The smallest possible unit of data, each bit being either equal to 0 or to 1.
  
• Bit-image or Bitmap - Representation of graphics or typefaces by dividing their shapes into equal sized dots which are stored as digital data, often with one bit representing each dot.
  
• Body text - The main portion of text in an article, brochure or book as opposed to headings and figure captions.
  
• Bold - Text in an emphasised form, appearing darker than ordinary text. Bold is used for emphasis, for example, in headings.
  
• Byte - The smallest unit of data that a computer can independently access. It consists of eight bits and may be regarded as representing a number between 0 and 255.
  
• Caption - A short piece of text identifying the contents of an adjacent picture, diagram or table.
  
• Caret - A special form of cursor used in software handling proportionally spaced characters. In !Edit and !Draw it is a red vertical bar whose serif-like extensions at each end make it resemble a capital "I". The next character to be printed appears just to the right of the caret. Centering Positioning the text so that it falls exactly midway between the margins, giving a symmetrical effect.
  
• Clip art - A collection of drawings and half tones supplied in the form of sprites or path objects for ad lib reproduction in the user's publications.
  
• Collating - Collecting together the pages of a publication in the right order before stapling or binding.
  
• Condensed text - Characters that are narrower than normal. Cropping Trimming the edges of a picture so that the required subject appears in the centre.
  
• Cursor - In a word processor a mobile indicator of the point at which the next character will appear on the screen. It may or may not blink; it may take the form of an underline or square of different colour.
  
• Descender - Part of a character which extends below the "line" on which the character is considered as sitting. Examples are the tails of such characters as "g", "p" and "y".
  
• Dither pattern - A pattern of pixels of alternating colours used to achieve the effect of intermediate colours. Examples can be seen by using the RISC OS Desktop environment in screen Mode 0; dither patterns of black and white are used to represent various shades of grey.
  
• Dot matrix printer - A kind of printer which prints text or graphics on paper by building up a pattern of dots. The dots are created by blows from the wires (usually 9 or 24 in number) in the print head via an inked ribbon.
  
• Drop capital - An oversize capital letter at the start of a paragraph. It usually occupies the start of the first three or four lines.
  
• Drop shadow - A black or grey simulated shadow behind text or graphics in a box giving the illusion that the box is floating in space above the page.
  
• Em - A unit of length at one time used by printers, equal to 1/6 inch or 12 points. It is so named because at one time it was regarded as the standard width of a 12 point capital "M". The unit is not often used today, but its name persists in the "em dash", a dash of supposedly the same length as a capital "M".
  
• Em dash (-) - ASCII code 152 in Acorn outline fonts. A punctuation mark used in place of commas for expressing apposition. Example: "The BBC Microcomputer - a machine at one time very popular in education - had only 32 Kbytes of RAM".
  
• En dash (-) - ASCII code 151 in Acorn outline fonts. A punctuation mark used in place of the word "to" in such expressions as "the 1939-1945 war".
  
• Figure (1) - A numeral as opposed to an alphabetical character, a punctuation mark or symbol.
  
• Figure (2) - A diagram, drawing or photograph illustrating an article or publication.
  
• Footline - A line at the foot of the page in magazines giving the magazine title (normally on the left-hand pages) and issue date (normally on the right-hand pages).
  
• Graphics - Any material which can appear on a printed page or on a monitor screen which does not consist of text. Graphics includes lines, boxes, circles, geometrical shapes, line drawings, sprites and half tones.
  
• Half tone - An illustration which uses many intermediate shades between the current ink colour and the current paper colour. Photographs reproduced for printing are "screened" into dots whose size determines the apparent shade of the area-larger dots will appear darker. The laser printer drivers for RISC OS include routines which convert sprites for half tone reproduction. This allows images captured by scanners to be incorporated into DTP and !Draw documents.
  
• Hanging indent - A form of paragraph setting in which the first line of the paragraph is full width and subsequent lines are indented.
  
• Heading - A title or subtitle usually distinguished from body text by use of a different style or size of print.
  
• Headline - A very large heading designed to attract the reader's attention to an important item.
  
• Icon - A small picture provided as a sprite which is used on screen to represent an application, utility or facility provided by an application. To start the application or use the facility, the mouse is moved so that the pointer is over the application and then the SELECT button on the mouse is clicked.
  
• Indent - Moving the left-hand edge of the text to the right. An indent may apply to just one line, as often used at the start of paragraphs, or over many lines, eg in quoted matter or in hanging indents.
  
• Inferior - See subscript
  
• Ink jet printer - A kind of printer which forms characters from dots made by blowing tiny jets of ink on to the paper. Quality is very variable, but some types give results almost as good as a laser printer.
  
• Italics - Slanted text thus: italics. Italics are used to emphasise passages, sometimes to represent quoted matter and often to represent titles or foreign words. Justified Text which is "justified"-some call it "doubly justified"-has its right-hand and left-hand margins perfectly straight. The widths of the word spaces are adjusted to make all lines the same length, except in lines which fall at the end of paragraphs.
  
• Kilobyte (Kbyte) - A unit of data equal to 1024 bytes. Landscape Use of paper with the longer sides horizontal, as on most "landscape" paintings. !Draw supports landscape pages, but scrolling and printing take much longer than for the alternative, portrait pages.
  
• Laser printer - A type of printer which produces very high quality text and graphics very quickly. Its main disadvantage is its cost.
  
• Leading - The space between lines of text on a printed page, so called because at one time strips of lead alloy in standard thicknesses of 1 point or 2 point were inserted to space out lines regarded as too close.
  
• Ligature - A compound character consisting of two characters joined together Examples are the "fi" and "fl" characters found in ASCII codes 158 and 159 Acorn outline fonts.
  
• Lithography - A form ot printing which relies on the immiscibility of water and oil. An image of the page is formed on the flat surface of a "plate" as a pattern of areas of water and oil- based ink. See also offset lithography.
  
• Margin - The area of normally unprinted space between the page contents and the edges of the page.
  
• Megabyte (MByte) - A unit of data equal to 1024 Kbytes or 1,048,576 bytes.
  
• Mouse - A piece of hardware which is used to move a pointer, caret or the cross-hairs on the screen to provide fine control of graphics functions as well as for selecting facilities indicated by icons.
  
• Non-Break Space (NBSP) - A character (code 160) which appears identical to a normal space (code 32) but which is treated by applications as a normal printed character in that lines cannot be split at a NBSP. It is also useful in providing paragraph indents in justified text since the width of the NBSP is fixed, whereas that of the normal space varies in justified text.
  
• Object - In !Draw any item in a drawing is an object or part of an object. A !Draw file consists of a sequence of "segments" each describing an object and containing sufficient data to allow that object to be reproduced. One object may overlap another and may totally obscure it. Oblique The name used for italics in some fonts.
  
• Offset lithography - The most commonly used method of printing books, magazines and newspapers. The image on the plate is formed as in conventional lithography, but the plate is wrapped around a cylinder and a rubber blanket roller transfers the image to the paper. The resulting rotary machine is capable of faster operation than conventional reciprocating presses.
  
• Outline font system - A system of font management in which details of the characters in each font are stored as plotting instructions. This has the advantage that any size of character can be produced without loss of resolution.
  
• Path object - In !Draw an object composed of one or more "paths" which may be straight lines, curved lines or moves which do not draw lines.
  
• Photocopier - A machine that produces copies of documents by an essentially photographic/electrostatic process. A photocopier may be used to produce multiple copies of documents produced by DTP quite economically.
  
• Pi-font - Jargon for a font containing special symbols rather than the normal alpha-numerics and punctuation marks. Examples are Acorn's Selwyn based on Zapf Dingbats and Beebug's SymbolB.
  
• Plate - In litho printing a sheet of paper, plastic or metal on to which the image of the page being printed is transferred by photocopying.
  
• Point - A unit of length still widely used in the printing and associated industries. One point equals l/72 inch. Font sizes are specified in points, the number of points representing the distance from the apex of the tallest character in the font to the bottom of the longest descender. For body text in books, magazines and newspapers, fonts of size 7 to 10 points are most frequently used.
  
• Pointer - An arrow on the screen which is moved as the mouse is moved on the desktop.
  
• Portrait - Use of paper with its longer sides vertical as in most "portrait" paintings.
  
• Printer - A piece of hardware which puts text or graphics on paper in response to the computer. See laser, dot matrix and ink jet.
  
• Printer driver - A piece of software which processes the data being sent to the printer, ensuring that it is in a suitable format.
  
• Proportional spacing - The characters used on standard typewriters and also the "system font" in RISC OS computers all have the same width. In most typefaces used in professional printing, however, the characters have various widths according to their design. Compare, for instance, the width of an "i" and that of a "W". Proportionally spaced systems allow characters to have as much or as little width as their design demands.
  
• Ranged left - Sometimes called "unjustified". Text printed with a straight left margin and ragged right margin, as on a standard typewriter.
  
• Ranged right - Sometimes called "fully indented". Text printed with a straight right margin and ragged left margin.
  
• Roman text - Normal upright text as opposed to italic or oblique.
  
• Sans-serif - A typeface in which the characters lack serifs. Best known examples are the Helvetica-style fonts such as Acorn's "Homerton" family or Beebug's "SwissB".
  
• Scanner - A device which converts paper documents to machine- readable data. Inexpensive hand scanners are simply moved over the document, an image appearing on the screen of the text or graphics on the document. More sophisticated scanners incorporate document feed facilities, giving more accurate conversion of data. The associated software for RISC OS allows the captured image to be saved as sprites which can be edited in IPaint and incorporated into !Draw documents.
  
• Screendump - The process of copying the contents of the current monitor display (or the pixel structure of a sprite) to a printer, whereby each pixel or group of pixels is represented by a dot or group of dots on the paper.
  
• Screening - The process used by the printing trade to convert areas of solid grey or colour to a pattern of black and white dots that can be printed satisfactorily. !Draw does provide a form of crude screening when printing out coloured or intermediate grey matter.
  
• Scrolling - Movement of the entire screen contents so that in a wordprocessor, DTP or art program, for example, another part of the document is seen.
  
• Serif - A protrusion at the end of a stroke in a character to give it style and make it easier to read. Note the serifs, four in all, at each of a capital "1" in a serif font such as Acorn's Trinity" family. There are also typeface styles which lack serifs and are commonly referred to as "sans-serif" fonts.
  
• Sprite - A graphical object in which the information describing it is held as a series of numbers defining the colours of all the pixels within it. A portion of a screen or even a whole screen can be saved as a sprite. RISC OS has a very sophisticated sprite handling system which allows sprites created in one screen mode to be displayed in other screen modes. Sprites can be created and edited in the RISC-OS application i.Paint.
  
• Subscript (or inferior) - Characters written below the line level and normally in a smaller typeface, as in chemical formulae.
  
• Superscript (or superior) - Characters written above the line level and normally in a smaller typeface, as in indices and exponentials, eg 1,000,000 = 1 x 10[superscript 6] = 1 x l06.
  
• Table, tabular matter - Matter displayed in rows and columns such as mathematical tables, transport timetables, tables of contacts' names and telephone numbers or the results of scientific experiments.
  
• Text - A portion of data consisting of printable characters (numbers, letters, punctuation marks and other symbols) which in a computer would be stored as a string of ASCII codes.
  
• Text area object - In !Draw an area of the document displaying text created in !Edit and using a special format. The size of the characters is determined by commands in the text; resizing the text area in !Draw simply causes the text to rearrange itself within the area without changing the size of the characters themselves.
  
• Text object - In !Draw an object containing a line of text entered at the keyboard using '.Draw's own text facility. Resizing a text object alters the size and possibly the proportions of the characters in the text object.
  
• Toner - The powdered ink used in photocopiers and laser printers. It is transferred to the paper via a roller electrostatically and is fused into the paper by heat.
  
• Unjustified - See "Ranged left".