Artwork File Types

There are two broad categories of artwork that can be printed from a personal computer: raster and vector images.

A raster image, also referred to as a bitmap, is composed of a grid of pixels. The grid, when enlarged sufficiently resembles a mosaic made from square tiles.

The examples above show a scanned Tiff photographic image at the original size and then blown up to 400%.

In vector images, picture elements are defined mathematically as lines or curves and can have solid, gradient or patterned color fills.

The examples above show an illustration at original size and then blown up to 300%.

Vector artwork is created in illustration and drawing applications such as Adobe Illustrator and CorelDRAW. Page layout applications, such as QuarkXpress and PageMaker also allow you to create simple vector artwork with their drawing tools.

All computer fonts, at least in the form used by printers are vector based as well.

Resolution and Scaling of Raster Images

While a 72 dpi raster image appears sharp on your monitor, the same image would likely appear pixilated (or "jagged") when printed to a color printer.

For best results try to keep scanned, bitmap images as close to their original size as possible (this will also help reduce the size of your document file). Although the color printer may be rated at 400 dpi - for practical purposes an image resolution of no more than 200 dpi will yield the highest possible quality for electronic color printing.