Dahlgren: A dampening system for printing presses which utilizes more alcohol (25%) and less water; this greatly reduces the amount of paper that is spoiled.
Dampening: An essential part of the printing process whereby cloth covered rubber rollers distributes the dampening solution to the plate.
Dandy Roll: During the paper making process while the paper is still 90% water, it passes over a wire mesh cylinder (dandy roll), which imparts surface textures on the paper such as wove or laid. This is also the stage where the watermark is put onto the paper.
Deckle Edge: The rough or feathered edge of paper when left untrimmed.
Deep Etching: The etching or removal of any unwanted areas of a plate to create more air or white space on the finished product.
Delete: An instruction given to remove an element from a layout.
Demy: A term that describes a standard sized printing paper measuring 17.5 x 22.5 in.
Densitometer: An optical device used by printers and photographers to measure and control the density of color.
Density: The lay of paper fibers relative to tightness or looseness which affects the bulk, the absorbency and the finish of the paper.
Density: The degree of tone, weight of darkness or color within a photo or reproduction; measurable by the densitometer. Reference, densitometer.
Descender: A term that describes that portion of lower case letters which extends below the main body of the letter, as in "p".
Diazo: A light sensitive coal tar product used as a coating on presensitized plates, as well as overlay proofs.
Die: Design, letters or shapes, cut into metal (mostly brass) for stamping book covers or embossing. An engraved stamp used for impressing an image or design.
Die Cutting: A method of using sharp steel ruled stamps or rollers to cut various shapes i.e. labels, boxes, image shapes, either post press or in line. The process of cutting paper in a shape or design by the use of a wooden die or block in which are positioned steel rules in the shape of the desired pattern.
Die Stamping: An intaglio process for printing from images engraved into copper or steel plates.
Digital Proof: Color separation data is digitally stored and then exposed to color photographic paper creating a picture of the final product before it is actually printed.
Dimensional stability: The qualities of paper to stabilize its original size when undergoing pressure or exposed to moisture.
Diploma: A fine paper made specifically for the printing of diplomas, certificates and documents.
Direct Screen Halftone: A color separation process using a halftone negative made by direct contact with the halftone screen.
Display Type: Any type that stands out from the rest of the type on a page which attracts attention of the reader.
Distribution Rollers: In the printing process, the rubber coated rollers responsible for the distribution of ink from the fountain to the ink drum.
Doctor Blade: A term in gravure printing which refers to the knife-edge that runs along the printing cylinder; its function is to wipe the excess ink away from the non-printing areas.
Dog Ear: Occurs when you fold into a fold (such as a letter fold). At the side of one of the creases you get an indentation. It may look like a small inverted triangle.
Dot: The smallest individual element of a halftone.
Dot Gain: Darkening of halftone image due to ink absorption in paper causing halftone dots to enlarge. Terms to describe the occurrence whereby dots are printing larger than they should.
Draw-down: A method used by ink makers to determine the color, quality and tone of ink. It entails the drawing of a spatula over a drop of ink, spreading it flat over the paper.
Drier: A term that describes any additives to ink which encourages the drying process.
Drill: The actual drilling of holes into paper for ring or comb binding.
Drop Folio: Page number printed at foot of page.
Drop Shadow: A shadow image placed strategically behind an image to create the affect of the image lifting off the page.
Dry Mount: Pasting with heat sensitive adhesives.
Dry Offset: Process in which a metal plate is etched to a depth of 0.15 mm (0.006 in), making a right-reading relief plate, printed on the offset blanket and then to the paper without the use of water.
Ductor Roller: The roller between the inking and the dampening rollers.
Dull Finish: Any matte finished paper.
Dummy: A term used to describe the preliminary assemblage of copy and art elements to be reproduced in the desired finished product; also called a comp.
Dummy Model: Resembling finished piece in every respect except that the pages and cover are blank, used by the designer as a final check on the appearance and +feel+ of the book as a guide for the size and position of elements on the jacket.
Duotone: Color reproduction from monochrome original. Keyplate usually printed in dark color for detail, second plate printed in light flat tints. A two-color halftone reproduction generated from a one-color photo.
Duplex Paper: Paper which has a different color or finish on each side.
Dutch: Any deckle edged paper, originally produced in the Netherlands. Reference, deckle edge
Dye-Based Ink: Any ink that acquires its color by the use of aniline pigments or dyes. Reference, aniline.