Bitmap - An image format that only defines an image in terms of black and white. A bitmapped image is generally used to define line art because its elements can only be black and white, unlike a grayscale image. In general, a bitmapped image will require a higher resolution to render good quality line art (1000 dpi or higher). A bitmapped image is also known as a 1-bit image.
BMP - (Bit Map Picture) This is the standard bit-mapped graphics format used in the Windows environment. By convention, graphics files in the BMP format end with a .BMP extension. It should be noted that modern BMP formats can now store colour information, although it is not ideal for printing.
Bleed - When colour, pictures and/or type go to the edge of the page they need to be extended past the edge to account for paper movement.
Byte, B. - A set of bits (normally 8, but sometimes more) that represent data, such as a single text character.
CMYK - (Cyan, Magenta, Yellow & Black) Colour palette used for printing. Ink is mixed to form desired colours.
Colour Correction - Adjusting the picture's colour and density to match a desired look.
Continuous Tone - Refers to images that have a virtually unlimited range of colour or shades of grays. Photographs and television images, for example, are continuous-tone images. In contrast, computer hardware and software is digital, which means that they can represent only a limited number of colours and gray levels. Converting a black-and-white continuous-tone image into a computer image is known as gray scaling.
Continuous-tone printers can print each dot at many different shades of lightness and darkness. Though this isn't true continuous-tone because the level of shades is limited, there are enough shades (256 or more) so that the difference between one shade and the next is imperceptible to the human eye.
Dot Gain - The amount of ink that soaks into the paper, making pictures look darker.
DPI - (Dots Per Inch) The resolution of an image or how many pixels are defined in a horizontal and vertical linear inch. The more correct term is pixels per inch, however dots per inch is often used instead.
Duo-tone - A picture that contains only 2 colours. Example: Sepia toned wedding pictures.
8-bit - A colour gamut that contains 256 different colours
EPS - (Encapsulated Postscript) File format, commonly used for line art, duo-tones, clipart and other vector images.
FTP - (File transfer protocol) A way of transporting information from one computer to another via the Internet.
Fonts - Computer support files that determine how type is styled on screen and in print.
Gamut - In colour reproduction, including computer graphics and photography, the gamut, or colour gamut, is a certain complete subset of colours. The most common usage refers to the subset of colours which can be accurately represented in a given circumstance, such as within a given colour space or by a certain output device.
GIF - (Graphics Interchange Format) A file format recommended for internet images NOT images for print.
Gigabyte, GB, gig - 1024 Megabytes (MB), which is 2^30 bytes, or 1,073,741,824 bytes. It is sometimes used to refer to 1000 Megabytes.
Halftone - The reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size or in spacing. "Halftone" can also be used to refer specifically to the image that is produced by this process.
Where continuous tone imagery contains an infinite range of colours or greys, the halftone process reduces visual reproductions to a binary image that is printed with only one colour of ink. This binary reproduction relies on a basic optical illusion-that these tiny halftone dots are blended into smooth tones by the human eye.
Image area - The maximum area to place pictures & text on a page. You have to leave blank space outside this area for the press to grab the paper and move it through the machine.
Impositioning - (digital stripping) Arranging pages in order so when printed will be in the proper position when folded & cut.
Jaggies - The effect caused by images or lines being rendered at too low a resolution. It can easily be defined as a stair-stepped effect giving the line or image a rough appearance. By increasing the resolution, we can reduce the stair-stepped effect. It is important to remember though that once an image has been saved at a lower resolution it cannot be "rezzed up" to a higher resolution. The resolution will in fact increase, but the quality of the image will not increase very much.
JPEG, JPG - (Joint Photographic Experts Group) JPEG is a standards committee that designed an image compression format. The compression format they designed is known as a lossy compression, in that it deletes information from an image that it considers unnecessary. JPEG files can range from small amounts of lossless compression to large amounts of lossy compression. This is a common standard on the WWW, but the data loss generated in its compression makes it undesirable for printing purposes.
Kilobyte, KB., K - 1024 bytes (1024 is 2^10), but sometimes used to refer to 1000 bytes.
LPI - (Lines per inch) Lines Per Inch. The number of lines per inch on a halftone screen. As a general rule, the higher the lpi, the higher the printed resolution. Example: Newspapers are usually 85 lpi and Magazines are 150 lpi.
Line Art - Artwork made of solid blacks and whites, with no tonal (gray) values.
Megabyte, MB., Meg - 1024 kilobytes (KB). 1024 is 2^20 bytes, which is 1,048,576 bytes. A megabyte usually refers to 1,000,000 bytes when used to describe disk storage capacity and transmission rates.
Moiré - The noticeable, unwanted pattern generated by scanning or rescreening a piece of art that already contains a dot pattern. This effect can also be caused by the misalignment of screen angles in colour work.
1-bit - A colour gamut that has only one colour (taking white as the colour of paper) it is solid black.
Output - Turning a digital file into a physical printed piece.
PDF - (Portable Document Format) File Format. The best way to package your files for press at OWP. We also use PDFs for your electronic PROOFS.
Platesetter - A device that uses laser light or thermal imaging to expose printing plates at high dpi resolution, usually 1200 dpi or higher. When generating screens or dots for halftones, each dot is created from the smaller dots that are determined by the dpi resolution. Platesetters come in many different sizes and formats. They can be configured to make many different sizes of plates, including plates for large presses such as the OWP's web presses.
PMS - (Pantone Matching System) A standard colour spectrum, that designers and printers use to have a colour looking the same.
Postscript - A page description programming language created by Adobe Systems Inc. that is a device-independent industry standard for outputting documents and graphics.
PPI - (Pixels per inch) Exactly the same as DPI.
Resolution - Resolution, in a nutshell, is simply a method for describing level of detail(or quality). Usually measured in DPI. Low DPI(i.e., 72dpi) results in a printed image that looks very poor due to the small number of dots per inch used when the image was scanned. By contrast, the higher the DPI when scanned(i.e., 300, 600, 1200), the better the printed image will look.
RGB - (Red, Green & Blue) Colour palette that you see on a computer monitor & TV set that uses light to form colour. Can not be used in printing. Colours you see on screen may not match their printed versions.
16-bit - A colour gamut that contains over 10 thousand colours.
Scanning - Taking a printed image or type and making a digital copy to use on a computer using a scanner.
Sit, Sitx - A method of compressing files. Usually Mac based computers use .sitx format compression.
Spot Colour - A spot colour is an extra colour in a job other than black or CMYK, normally a PMS colour. (i.e. Black & PMS 185).
Storage Media - A container that records digital information that can be retrieved by a computer. Example: Floppy disk, Hard Drive, Cd, DVD, etc...
24-bit - A colour gamut that contains 16 million different colours.
Tiff - (Tagged Image File Format) File format commonly used for pictures.
Trapping - Expanding & shrinking different colours to compensate for paper movement when printing. Colour may be affected if file is not properly trapped.
True Type Font - Font used mainly for desktop printers.
Type 1 Font - A postscript font that uses 2 files (screen & printer) to print properly. This font type is recommended by OWP.
Vector Image - Mathematical information that doesn't require any dpi. Can be easily shrunk or enlarged without any worry. Example: Clipart, converted text, line art drawn on the computer.
Zip - A method of compressing files. Usually Windows based computers use .zip format compression.
