Art Terms 

What is CMYK?

CMYK is a print process that uses four colours - cyan (C), magenta (M), yellow (Y) and black (K) to produce all other colour ranges. It's used for most full-colour commercial printing.

What is RGB?

RGB is an additive colour model in which three primary colours of light (red, green and blue) are combined in varying intensities to produce all other colours. Monitors, scanners and the human eye use RGB to produce or detect colour.

 

What is Spot Colour?

This is a colour that is reproduced using a single ink. Spot colour swatch books and links are provided by companies such as Pantone.

 

What is DPI?

DPI stands for dots per inch and is a measure of the resolution of a display or output device.

 

What is Resolution?

Resolution is a measure of the size of pixels or dots that compose a bitmap.

 

What is LPI?

Lines per inch; a measure of the screen frequency of a halftone.

 

What is PostScript?

This is a programming language used to describe text, shapes and bitmaps of each page of a publication. Postscript can be used to transfer a print job from a desktop computer to a printing device such as an image setter.

 

What is PPI?

Pixels per inch; a measure of the scanning resolution and the resolution of a bitmap.

 

What is a Bitmap (BMP)?

A bitmap is an image composed of a rectangular grid of squares called pixels (picture elements). Each pixel contains information that describes whether it is black, white or has a colour value. When working with bitmap images, you edit pixels rather than objects or shapes. A bitmap image is resolution independent - that is, it contains a fixed number of pixels to represent it's image data. As a result, a bitmap image can lose detail and appear jagged if viewed at a high magnification on-screen or printed at too low a resolution. BMP is the standard Windows image format.

 

What are Vector Graphics?

Drawing programs such as Adobe Illustrator, Freehand and CorelDraw create vector graphics. These are made of lines and curves defined by mathematical objects called vectors. Vectors describe graphics according to their geometric characteristics.  A vector graphic is resolution-independent - that is, it can be scaled to any size and printed on any output device at any resolution without losing it's detail or clarity.

 

What is EPS?

Encapsulated Post Script. This is a file format that supports both PC and MAC images. EPS files are platform independent. EPS format is used to transfer Postscript language artwork between different programs.

 

What is the difference between a GIF and JPEG?

A GIF (Graphics Interchange Format) is a bitmap file format commonly used to display indexed-colour graphics and images in HTML documents over the Web and other online services. GIF is a LZW (Lemle-Zif-Welch) - compressed format designed to minimise file size and electronic transfer time.

A JPEG (Joint Photographic Experts Group) is commonly used to display photographs and scanned images via email. JPEG retains all colour information in a bitmap image but compresses file size by selectively discarding data. The JPEG format supports CMYK, RGB and grayscale colour modes. A higher level of compression results in lower image quality and a lower level of compression results in better image quality.

Both forms are excellent for electronic use, but are not suitable for printing.

 

What is a TIFF image?

It's a bitmap file format that was specifically developed for page layout applications and is supported by all image editing applications. The TIFF format supports RGB, CMYK, grayscale and bitmap (black and white) files.

 

Is the process separation the same as colour separation?

Yes. This is a process of separating a colour image into primary colour components for printing - generally CMYK.  The term is also used to refer to the four pieces of film that result from the process of separating a colour image.

 

What is a PDF document?

A PDF (Portable Document Format) is used by Adobe Acrobat.  Adobe's electronic publishing software for Windows, Mac OS, UNIX and DOS. You can view and print PDF files using the Acrobat Reader software. PDF files can represent both vector and bitmap graphics.