AUTOTRAP
A software program that automatically applies trapping to film which is
output by imagesetters. Trapping is the precise relationship between two
ink colors when they butt together on a printed sheet. If no trap is added,
a white gap may appear between colors. If too much trap is added, a dark
line will appear where the colors overlap.

BLUELINE PROOF
Bluelines are inexpensive film proofs used to show content, page layout, folding, and color breaks on one or two-color orders. Images on blueline proofs appear in shades of blue to the viewer and show extensive detail in contrast, shading, and halftone resolution.

BOUND SIZE
The dimensions of a book or folded piece after it has been bound or folded into its finished state.

CMYK
The acronym for the four basic ink colors used in “process” color printing: Cyan, Magenta, Yellow and Black.

CHROMALIN PROOF
Chromalins are film proofs made using the DuPont system of mixing colored dye powders to approximate PMS colors, putting them into solution and applying them to a carrier sheet. The film controls where the image areas will appear. CMYK dyes are used when four-color proofs are needed. Chromalin proofs are the most expensive off-press proofing system discussed here.

COLOR KEY PROOF
Color Keys are film proofs that use colorized acetate overlay sheets to approximate four-color printing. Each of the process colors is applied to an overlay and then the overlays are registered to each other and taped down to a white piece of paper. Color Keys are one of the least accurate color proofing systems because the color is being viewed as dyes on plastic rather than pigments on paper.

COLOR SEPARATED LASERS
(see laser proofs)

COLOR SEPARATIONS
(see process color separations)

DIGITAL PROOFS
Digital proofs are produced from electronic art files before color-separated films or plates are generated. This is the least expensive point in the overall proofing process for making alterations to files. Some examples of digital proofs are lasers, phasers wax proofs, dye sublimation, and color copies from digital data.

DTP
is the acronym for Desk Top Publishing

DUOTONE
When a photograph is printed using two ink colors it is a duotone. The most common color combinations are black plus a color, but duotones can be created using two PMS ink colors.

DYE SUBLIMATION PROOF
A digital, non-film proofing process in which CMYK dye solutions are applied to a paper carrier to approximate the final color images.

DYLUX PROOFS
A dylux proof is an inexpensive film proofing system used to show content, page layout, folding, and color breaks on one or two-color orders. Images on dylux proofs appear in shades of blue to the viewer and show extensive detail in contrast, shading, and halftone resolution.

FILM
Film is photo-sensitized acetate sheets which are processed through exposure to light. Film carries the images to be printed. The acetate sheets are solid black before exposure. After exposure, the image areas become clear. Film is first used to make proofs and then, second, used to make metal printing plates.

FILM PROOFS
Film proofs are created using the negatives which have been output on an imagesetter. They are highly accurate representations of what the final printed product will look like and are given to clients for final review, approval, and “sign-off” before the printing plates are made and the order is put on the press. Some examples of film proofs are Dylux, Silverprint, Blueline, Chromalin, WaterProof, Color Key and Matchprint.

FLAT SIZE
The dimensions of a brochure or folded piece before it is folded up.

GRAY SCALE
The tonal range from a very light gray (1% dot) up to solid black (100% dot) in increments of 1%.

HALFTONE
The reproduction of continuous-tone artwork such as photography or pencil sketches, through a digital screening process which converts shaded images into solid ink dots of various sizes and concentrations. A few tiny dots will produce highlight areas. A heavy concentration of large dots will produce mid-tone and shadow areas.

IMPOSITION
The arranging of pages on a press sheet to ensure the correct order after the sheet is folded and trimmed.

LASER
The acronym for Light Amplification by Stimulated Emission of Radiation. A laser is an intense beam with very narrow band width that can produce images by electronic impulses from digital data.

LASER PROOFS
Laser proofs are black and white or CMYK digital, non-film proofs which can be run out as composites or as color separated sheets. Lasers are used to check spelling, grammer, image placement, photo cropping and the proper separation of colors. Lasers are the least expensive form of proofing available. However, they are also the least accurate for image detail and color matching. Composite laser proofs indicate that all colors which will print have been used to produce the laser print-out. Color-separated laser proofs indicate that each ink color has been printed out on its own separate laser print-out. (e.g. CMYK separated laser proofs result in four sheets of laser print-outs; one each for the cyan, magenta, yellow and black.)

LITHOGRAPHY
Lithography is the printing process based on the theory that water and oil will not mix. The lithographic printing process uses a planographic plate to control where the printed image will appear. This plate is sensitized to be ink-receptive in the image areas and water-receptive in the non-image areas. After the plate is placed on the printing press, ink is applied to the surface of the plate and stays in the image areas. A miniscule amount of a watersolution is applied to and stays in the non-image areas of the plate defining where the ink is positioned to an accuracy of 1/1000 of an inch.

NEGATIVE-PROCESSED
Printing plates that are created with film negatives are called negative-processed printing plates. Negative-processing is also used to make proofs for clients before the printing plates are made.

OFFSET PRINTING
The term offset is often used interchangeably with lithography. In fact, lithography is the printing process based on the theory that oil and water don't mix and often uses the offset process for printing an image. Offset is the process whereby a printing plate first transfers its inked image areas onto a rubber blanket mounted on a cylinder in the printing press and then the rubber blanket transfers (or offsets) the inked image onto the paper as it passes through the press.

OUTPUT (when used in printing)
Output is the end result of converting electronic art files into the prepress materials used for printing production. Imagesetters output film negatives or film positives which are used to make printing plates. Platesetters output the printing plates used on the press.

PHASER WAX PROOFS
Phaser proofs are digital, non-film proofs which employ liquified colored crayons in the CMYK colors to create four-color images. Phasers use a 300 dpi resolution and output the image on paper—similar to a laser proofer.

PLATES
Plates are the carriers of the images that are to be printed on paper. One printing plate is required for each ink color printed. Metal plates are the only way to produce high quality, close-register printed images. Plates can also be made out of plastic and paper.

PMS COLORS
PMS stands for Pantone Matching System and was developed for color identification. The system assists clients, designers and printers in the communication process for color specification on printing orders. Each PMS color has a unique number and formula for ink mixing. PMS colors are also referred to as “spot” colors.

PROCESS COLOR
The four basic colors of ink used in process color printing are cyan, magenta, yellow and black. These ink colors are transparent and “process” with each other when overprinted in predetermined amounts. i.e. when cyan overprints yellow, it produces green, when yellow overprints magenta, it produces orange. Controlled screen tint combinations of the four basic colors allow the full spectrum of colors to be produced on a printing press.

PROCESS COLOR SEPARATIONS
Color separation refers to the breaking down of any full-color image into the four basic ink colors used in printing. The making of a color separation involves the use of a laser light scanner which, through the use of four color filtering systems, can “read” and record the amounts of cyan, magenta, yellow and black that is present in any particular area of a color original. The recording of this data is converted into digital form and saved to a computer for further processing and placement into page layout programs.

RESOLUTION
The quantification of output quality designated in dots per inch (dpi) when applied to paper output and in lines per inch when applied to film output. Laser printers commonly hold resolutions of 300, 600, 800 and 1200 dpi. Film output units (imagesetters) have variable resolution output; but are most commonly specified based on the surface type of papers to be printed. Newsprint can hold a resolution from 65 to 100 line screen. Uncoated papers typically use 120, 133 or 150 line screens. Coated papers can hold resolutions of 133, 150, 175 and 200+ line screens.

SHEET-FED PRINTING
Sheet-fed printing is the process where pre-cut sheets of paper are fed through the printing press rather than paper being fed off rolls (or webs).

SILVERPRINT PROOFS
A silverprint is an inexpensive film proofing system used to show content, page layout, folding, and color breaks on one or two-color orders. Images on silverprints appear light gray or “silver” to the viewer and show extensive detail in contrast, shading, and halftone resolution.

SPOT COLORS
are PMS colors.

SPOT COLOR SEPARATIONS
When spot colors (or PMS colors) are being used in a printing order the identification and assignment of each color can be done in a page layout program. This process is done by the designer of the art files. When a printshop receives electronic files, one of their routine jobs is to give a proof back to the client to verify that the spot color separations appear in the correct locations.

STRIPPING
Stripping is the process where film negatives are positioned (imposed) in preparation for making the printing plates. Litho strippers lay the films down on carrier sheets. A proof is then made from the “stripped up” negatives for the client to review and approve. After approval or corrections, the same stripped up negatives are then used to make the printing plates.

TEKTRONIX PROOF
Techtronix are digital color proofs which are used for preliminary proofing of the text, scans, cropping, sizing and color breaks. They are not accurate enough to use as final color proofs.

WATERPROOF
After the Chromalin proof became obsolete, DuPont introduced the WaterProof as one of the most accurate color proofing systems for process color (CMYK) printing. It is a film proofing system that employs the same color pigments used in printing inks. The use of color pigment, instead of dyes or colored acetate overlays, is the reason the color of the WaterProof is so accurate when compared to an actual press sheet.

WEB-FED OFFSET
Web-fed printing is the process where paper runs through the printing press from a roll and then is trimmed into sheets.