Steaff indexed, no dithering Steaff indexed, dithered Look at Steaff's eyes. Notice that in the dithered version, the black dots are more evenly distributed. Without dithering, colors are merely reduced to the closest match in the palette, which accounts for the big dark blotches in Steaff's pupils in the first example. One big problem, though. If you're an online cartoonist, you are most likely going to have to be very concerned with file size and bandwidth.
Somebody somewhere has to pay for files to be transferred around on the internet.
You're going to want to reduce that file size to a point where it only takes three cents or less to be transferred. Otherwise, you may by whacked with a bill from your host that you can't afford to pay. This isn't a problem for webmasters on free servers like GeoCities and Keenspace, and, hopefully, these entities will continue to provide those services free of charge. But even if you're not worried about bandwidth, you still want to impress your visitors with a relatively quick-loading comic strip. If a new visitor has to wait more than half a minute for your comic strip to load on the page, they may get bored and move on, and never come back.