In addition to specifying background color, web page creators can specify a background pattern. A background pattern is usually a small GIF image designed to repeat itself over the page in such a way that this repetition is seamless.
A pattern is easily added to a document by slightly modifying the body tag:
- <BODY BACKGROUND="bg-grey.gif">
Patterned backgrounds should be used with restraint because they can significantly slow download time. Because of this, they should be kept small and shouldn't be used at all on pages that already contain a large number of images.
Also, no matter how subtle patterns are, they almost always impair reading. Even if this effect is only slightly noticeable, it should be carefully considered by the page designer. (While interlacing GIFs ordinarily gives the perception that images are downloading more quickly, interlacing background patterns slows page loading so GIFs used for background patterns should not be interlaced.)