Preparing graphics for a website is a journey into the unknown: You've got no idea what kind of monitor folks will use to view your images, how fast (or slow) their Internet connections are, or what kind of web browsers they've got. It's a proposition riddled with variables that you have no control over; all you can do is prepare your graphics well and hope for the best.
Your challenge as a designer boils down to finding a balance between image quality and file size. Premium-quality, minimally compressed JPEGs look stunning under almost any conditions—but if your site visitor has a pokey dial-up connection, she might decide to click elsewhere rather than waiting for the darn thing to download. On the other hand, if you try to satisfy the slowest common denominator by making ultra-lightweight images, you'll deprive those with broadband (high-speed) Internet connections from seeing impressive detail you've lovingly created.
Luckily, there are several tricks for keeping file sizes down and retaining quality. That's what this chapter is all about. You'll learn which size and file format to use when creating images destined for the Web. You'll also discover how to make animations; craft favicons (those tiny graphics you see in web browsers' address bars); mock up web pages, and publish professional-looking online photo galleries.
For a tutorial on creating your own custom Twitter page using Photoshop (Twitter is the 140-character blogging phenomenon), ...