Finally, contrast also affects readability. (8.5) Black text against a white background is easier to read than black text against a gray background. White text on a black background should be avoided-backgrounds do not print and users will be unable to read white text after it has been printed on white paper.

Characteristics of Web Typography

Typography is both visual and verbal communication. When scanning a page, readers first notice the visual hierarchy of the text established by size, color, punctuation, and graphic accents (Andres 62). They determine the relationship between words and pictures, headlines and the content that follows. (8.6) Once they develop a visual understanding of the page, users begin to read: "Typography is the balance and interplay of letterforms on the page, a verbal and visual equation that helps the reader understand the form and absorb the substance of the page content" (Lynch and Horton 79).

Although the basic rules of typography are similar for web page and print documents, type on screen differs from type on paper-the type on the web varies. Each time a web page is loaded into a browser, it is rebuilt: "Each line of text, each headline, each unique font and type-style is re-created by a complex interaction of the Web browser, the Web server, and the operating system of the reader's computer" (Lynch and Horton 79). (8.7) Because the page is reconstructed, fonts could be missing on the user's computer or could be overridden based on the user's set preferences. Thus, designers can never be certain how a page will look on the user's screen.