D Dagger and double dagger - symbols used mainly as reference marks for footnotes. Densitometer - a device for measuring the closeness of substance at a specific location on film or printed product, either by reflected or transmitted light. Densitometers vary in their sophistication and the number of features provided, such colour, black-and-white, read-out memory, computer printout etc. Desktop publishing - a generic title given to the introduction of personal computers (PC) to typesetting, page composition and image handling. The combination of all these gives electronic control within a single system of what was traditionally a specialist and segmented operation. Die - a hardened steel engraving stamp used to print an inked image. Used in the production of good quality letter headings. Digital - describes the use of digital pulses, signals or values to represent data in computer graphics, telecommunications systems and word processing. Digital page composition - DPC, also known as EPCS (electronic page composition system) or CEPS (colour electronic page system). A system designed to take a range of page elements (text, line-work and images) and integrate them into a user-specified format. Image and text input to the system arrive on magnetic tape, by direct system interconnection or directly from an input scanning system. Display type - larger type used for headings etc. Normally about 18 point or larger. Dot matrix printer - a printer in which each character is formed from a matrix of dots. They are normally impact systems, ie a wire is fired at a ribbon in order to leave an inked dot on the page, but thermal and electro-erosion systems are also used. Double density - a method of recording on floppy disks using a modified frequency modulation process that allows more data to be stored on a disk. Double page spread - two facing pages of newspaper or magazine where the textual material on the left hand side continues across to the right hand side. Abbreviated to DPS. Downloadable fonts - type faces which can be stored on a disk and then downloaded to the printer when required for printing. These are, by definition, bit-mapped fonts and, therefore, fixed in size and style. DPI (Dots Per Inch) - the measurement of resolution for page printers, phototypesetting machines and graphics screens. The greater the DPI, the finer the print. Drawn on - a method of binding a paper cover to a book by drawing the cover on and gluing to the back of the book. Drawn-on cover - A paper book cover which is attached to the sewn book by gluing the spine.
Drop cap - a large initial letter at the start of the text that drops into the line or lines of text below. Dry transfer (lettering) - Characters, drawings, etc, that can be transferred to the artwork by rubbing them off the back of the transfer sheet. Best known is Letraset. Dummy - A sample of a proposed job made up with the actual materials and cut to correct size to show bulk, style of binding, etc. Also a complete layout of a job showing position of type matter and illustrations, margins etc. Duotone - a halftone picture made up of two printed colours. Duplex Cutting - operation of converting a web paper into sheets on a cutting machine equipped with two cross-cut knives so that two different lengths of sheet can be cut simultaneously | 
