Web Type: Sizing art for the internet

A friend of mine was wondering what are the specific issues regarding sizing art for the internet. Can you explain this to me?

there are two issues regarding “size” of art - physical size (in bytes) and layout size (in width/height)

You have to have the two in harmony to have an optimized web page. You want the file size to be small enough to that it doesn’t take forever to load on a slow connection, yet large (layout wise) enough to see the image clearly.

With a program like photoshop you can “optimize for the web” which lets you scale the resolution (percent in jpg files, and # of colors for gif files) in real-time. You can see how the number of colors effects the look of picture and the load time all in the same pane. this doesn’t change the layout size, however.

When considering web page layout, remember that the “standard” for screen resolution is now 600x800, meaning if your page is wider than 800 pixels in width, most people will end up scrolling side-to-side to see your entire page. so if you make art wider than 800 pixels, you may be screwed.

Another thing to consider is gif vs. jpg files. You want to make high-color photos (well, most photos) into jpg files and graphic elements like buttons, nav bars, etc into gif files. it’s easier to scale down the number of colors in a gif when you have fewer colors to worry about.

there’s a lot more to say, and hopefully people will chime in with more. And hopefully I understood the OP correctly, or else I look like I like to hear myself think…

Actually this is the most detailed answer I got.

I know how to size art with a stat wheel, but I’m also looking for any guidelines as to ideal sizes from a points-and-picas standpoint (assuming there is an ideal).