The mechanism on a press for transferring dampening solution to the plate during printing.
cloth covered, parchment paper or rubber(bare-back) rollers that distribute the dampening solution to the press plate or ink roller.
The opposite of embossing. Instead of a raised image, letters or images are depressed into a sheet with a die.
The width of the wet sheet as is comes off the wire of a paper machine.
Feather-edged sheets that trace their origin back to early handmade papermaking when the pulp slurry seeped under the molding frame (deckle) causing the edges to feather.
A printer's tool used to make sure that ink color stays accurate and consistent throughout a press run.
The degree of darkness(light absorption or opacity) of a photographic image.
That part of a lower case letter which extends below the main body, as in "q".
Desktop Color Seperation
A data file that standard defined to assist in making color seperations with desktop publishing systems. Using DCS five files are created: four color files, containing the cyan, magenta, yellow and black image data, and a composite color viewfile of the color image.
Process of composing pages using a standard computer, off-the-shelf software, a device independent page description language like Postscript and outputting them on a printer of imagesetter.
The characteristic of a computer program or system that alllows different output devices to image the same file more or less the same.
Diazo - Offset Platemaking
A light-sensitive coating used on presensitized and wipe-on plates.
Diazo - Photography
A non-silver coating for contact printing.
Cutting shapes into paper using a metal-edged die or laser. This may be for the purpose of creating a decorative pattern or for funtional needs such as making a pocket folder.
An itaglio process for the production of letterheads, business cards, etc., Printing from lettering or other designs engraved into copper or steel.
Diffusion Transer ( Photography)
A system consisting of a photographic emulsion on which a negative is produced.
Diffusion Transfer (Plate Making)
A receiver sheet on which a positive of the image is transferred during processing.
Digital Color Proof
A digital proof is made directly from a digital file without the intermediate use of film. Digital proofs can be divided into two subgroups: preliminary and contract.
A computer that processes information in discrete digital form.
Printing Plates that can be exposed by lasers or other high energy sources driven by digital data in a platesetter.
Printing by plateless imaging systems that are imaged by digital data from prepress systems.
A computer peripheral device that converts an analog signal into a digital device.
Ability to maintain size; resistance of paper or film to dimensional change with change in moisture content or relative humidity.
Direct Screen Halftone
A halftone negative made by direct exposure from the original on an enlarger or by contact through a halftone screen.
Type set larger than the text.
A technique for alternating the values of adjacent dots to create the effect of intermediate values. Dithering refers to the technique of making different colors for adjacent dots or pixels to give the illusion of a third color.
A knife-edge blade pressed against the engraved printing cylinder which wipes away the excess ink from the non-printing areas.
Disk Operating System A program containing instructions for a computer to read and write data to and from a disk. An operating system (set of programs) that instructs a disk-based computing system to manage resources and operate peripheral equipment.
The individual element of a halftone. In AM screening the dots vary in size. In FM screening the dots are very small and usually all the same size.
Coated and uncoated papers tend to absorb ink in different degrees. To adjust for these varying absorption levels, printers alter the size of the dots in halftones and 4-color images to compensate for dot gain.
Tendency for the dots of halftones and 4-color images to print larger than they are on the plate.
Sending information to another computer or to output.
Dots per inch; the number of dots that fit horizontally and vertically in a one-inch measure. Generally, the higher the dpi, the sharper the printed image.
A term used to describe ink chemist's method of roughly determining color shade. A small glob of ink is placed on paper and drawn down the edge of a putty knife spatula to get a thin film of ink.
Portions of the originals that do not reproduce, especially colored lines or background areas. (Often on purpose)
Uses photo multiplier tubes (PMT) and produces color seperations wiht higher resolution and dynamic range than CCD scanners.
The process of applying a second layer of ink or varnish over a layer of dry ink that had been printed on a separate run through the press. Although more expensive, dry trapping provides a sharper image than wet trapping because the layer of ink or varnish isn't diluted by a first layer of wet ink.
A substance added to hasten drying.
Blank sheet(s) of paper folded in the same manner as the final job and marked with page numbers and heads; when unfolded, can be used to show page and copy positions.
A one-color halftone printed over a screen of a second color halftone.
A two-color halftone of the same image created with two screens, two plates and two colors. Generally the full tonal range is printed in black and the middle range of tones are printed in the second color to create an effect that is deeper and richer than a one-color halftone.
Printing on both sides of the paper in one pass through the printing device. Also referred to as “perfecting”.
Two sheets of paper that have been laminated together to feature a different color on each side.
A film for making positives from positives and negatives from negatives.
Digital Video Disk - An optical disk that can hold 4.7 GBs or more
Denisty difference between highlights and shadows of scanned subjects.