It can be used as a way to create simple variety in a design, such as the headers on this page. A full page of white text against a black background certainly creates contrast, but seems to be harder to read than black text on white. In addition to black text against white, and white text against black, red text is also a suitable color that creates good contrast against white, and is acceptable to those with visual impairments. Consider using the BOLD tag when using red text on a white background, or white text on a black background to improve the contrast between these color combinations. Textured backgrounds should be used sparingly and cautiously, and in most cases, it would be wise to avoid textured backgrounds completely.
Textured backgrounds have a tendency to greatly reduce the contrast between the background and text.
Text has a tendency to blend in with a textured background, reducing readability, and thus complicating web accessibility to the visually impaired. If a textured background is to be used on a web page. Experiment with it using text, and test it on several browsers. Tone it down and keep it subtle. Remember, it is a background, and should not overwhelm or overpower the content of the page.