Most users are dialling in on a telephone modem which could be as slow as 9600 bps through one of the Internet service providers or as fast as 28.8 Kbps through some local services. Schools and university dial-in services commonly connect at 14.4 Kbps. Large image files can slow any of these modem connections to a crawl. This second file could be a JPEG version which will display in Netscape or which will launch a separate JPEG application. The 16-colors in the figure to the right display attractively.
Original versions limit the background to a uniform gray.
This feature of the HTML protocols has a design impact on the appearance of the image on a Web page. However, if the page is being read by a older browser, or if the user has set options to locally override the color selections, the designer's efforts could produce a light rectangle on a gray, blue, or yellow page, rather than a silhouette. Masking is not as difficult as it sounds, nor as confusing as some desktop publishing applications have made it seem. Information in personal directories may disappear if the individual leaves the company or the institution. In general, imagemaps work on all browsers.