Offset printing help: Jargon, special terms used in design, printing and graphic arts

ASCII - (American Standard Code for Information Interchange). A fundamental set of codes which virtually every computer uses to store and exchange data. Files saved in ASCII typically have the .txt extension on the PC platform. Very useful for exchanging text and data.

Bleed - When ink printed on a sheet goes right to the edge, a piece is said to bleed. Bleeds usually require larger paper and therefore increased cost.

CMYK - Stands for Cyan, Magenta, Yellow and Black. K is a printer acronym for black. These are the colors used in 4-color process printing to reproduce most of the colors of the visible spectrum. CMYK is also a digital method of reproducing color images on a computer screen and outputting film. Using CMYK gives
desktop publishers a more accurate view of how a color image will look in the final printed process.

Color bars - A technique used to help keep ink color consistent throughout the press run. A series of squares of ink are printed at the back edge of a press sheet. These blocks are measured with a densitometer. See description below.

Contrast - the tonal gradation in an image between highlights, midtones and shadows. An image is considered "flat" if the highlight and the shadow areas are close to the midtone shade. An image is described as high contrast if the highlight areas contain very small or no dots and the shadow areas have very large dots which result in very dark tones.

Densitometer - An electronic device that measures the density of film or printed ink. In the printing process, this device measures the density of a printed block of ink. Used by pressmen to monitor the ink color and therefore help them keep the ink color consistent throughout the run.

Drop Cap - A typesetting style where the first letter in a section is larger than the rest.

Dynamic Range - a measure of a scanner's ability to capture an image's gradations from the lightest highlight to the darkest shadow.

"Em Dash" - punctuation mark that is like a long hyphen, it looks like this "-." The width of an em dash is the same width in points as the type itself. So named because the letter "M" was usually cast on a square body.

Finish - refers to the type of paper surface - can be gloss, dull, uncoated, smooth, vellum, laid, linen or felt.

Flush right (or left) - type that is set to line up on the right (or left).

Grade - a loose system used to classify paper quality.

Grayscale image - An image whose gray values run throughout the gray scale.

Halftone - a black and white representations of continuous tone, black and white or color, photos.

Highlight - areas of halftones that have very small dots (under 25%), or light in appearance. An example would be snow on a mountain.

I.P.H. - An acronym for Impressions Per Hour, a unit of measure for printing press speeds. Refers to the number of sheets printed per hour.

Keyline - thin rule sometimes put around images to provide a more clear definition of the image. Keylines should be at least .25 points or more.

Kerning - subtracting or adding space between character pairs in order to improve appearance. Some pairs that are commonly kerned are AT, OT, rs, rt, rw, ry and rn.

Leading (pronounced ledding) - the distance between lines of type, measured in points. If you specify typesetting as "10 on 11 (or 10/11)" you are calling for type that is 10 points tall and separated by 1 point lines.

Line up - A part of the make-ready process in the press department. Lines are drawn connecting the final trim marks on a sample sheet to determine if the pages are in the correct position.

Midtone - areas of halftones where the dots are medium in size, from 25% to 75%.

Negative - Film containing an image in which the values of the original are reversed so the dark areas appear light and vice versa. Negatives are an essential step in the printing process. Printing plates and proofs are exposed through negatives. Negatives are either shot on a graphic arts camera or output on an imagesetter from a computer.

Opaque - a sheet that has added chemical whiteners, brighteners and opacifiers.

Page Count - Refers to the number of pages in a booklet. For instance, 16 pages plus cover or 20 pages self cover. A page is defined as one side of one sheet.

Page Size - Refers to the final trim size of a piece. Common and economical sizes are 8 1/2 X 11, 5 1/2 X 8 1/2 or 6 X 9. Almost any other size is also available.

Perfect Binding - Also called adhesive binding, this method of bookbinding produces what is commonly known as a "paperback" book.

Pica - a unit of measurement, roughly equal to 1/16"

Perfecting Press - A type of printing press that prints both sides of a sheet at the same time.

Plus Cover - Refers to a booklet that uses a different cover stock for the cover or outer 4 pages. Usually the cover is a heavier stock than the interior.

PMS - an acronym for Pantone Matching System. A series of color charts showing blends of base inks. PMS books are the standard for ink color designation in the graphic arts industry. PMS books can be purchased on-line (www.pantone.com) and cost $120.00 for the basic book.

Point - another unit of measurement, there are 12 points per pica and approximately 72 points per inch.

Recycled - Describes paper that is partially comprised of material previously used by consumers. Frequently you see the term "10% post consumer waste." This means that 10% of the material used in the paper is of recycled origin.

Register - In printing, the act of printing two or more colors together with extreme accuracy. Pieces that are printed "in register" show clean, crisp edges and no white space between adjoining colors.
Make Ready - In manufacturing, the pre-production work required before one salable item is produced. In the printing department, this includes getting the required materials in place, mixing inks, putting the plate on the press, getting the color correct, and checking the sheet to the last proof.

RGB - Stands for Red, Green and Blue. A method of displaying color images on a computer screen. Computer screens use these colors just like a television. Files set up as RGB must be converted to CMYK in order to get an accurate view of how a color image will look when printed and in order to output film suitable for printing.

Schedule: When will the materials be ready, when do you need the finished product. Schedules can have an effect on the cost so it is important that you have as much information as possible. Even tentative schedules are useful for the estimating process.

Self Cover - Refers to a booklet that is printed on the same paper for all pages. Even if the cover as a different ink configuration than the interior, the booklet is still considered to be a self cover piece.

Shadow - the darkest areas of a halftone where the dots are the largest, over 75%.

Wash up - Cleaning the ink out of a printing press.

Widow - When a single line at the end of a paragraph contains only one or two words. Also describes when a single word wraps to the top of the next column or page.