HTML and CSS Reference
In-Depth Information
got 13 wood grains and 22 kinds of marbling, and I'm going to use them
all!").
In reality, texture-mapped backgrounds, except for the very clever
ones, add no information to your documents. The value of your docu-
ment ultimately lies in its text and imagery, not the cheesy blue swirly
pattern in the background. No matter how cool it looks, your readers are
not benefiting and you could be losing readability.
We advise you not to use the color extensions except for comparatively
frivolous endeavors or unless the extension really adds to the docu-
ment's value, such as for business advertising and marketing pages.
5.3.2.1. Problems with background images
Here are some of the things that can go wrong with background images:
•
The time to load the document is increased by the amount of time
needed to load the image. Until the background image is com-
pletely downloaded, no further document rendering is possible.
•
The background image takes up room in the browser's local
cache, displacing other images that might actually contain useful
information. This makes other documents, which might not even
have backgrounds, take longer to load.
•
The colors in the image may not be available on the user's dis-
play, forcing the browser to dither the image. This replaces large
areas of a single color with repeating patterns of several other
closer, but not cleaner, colors and can make the text more diffi-
cult to read.
•
Because the browser must actually display an image in the back-
ground, as opposed to filling an area with a single color, scrolling
through the document can take much longer.
•
Even if it's clear onscreen, text printed on top of an image invari-
ably is more difficult, if not impossible, to read.
