I'm totally new at this. My client wants a high rez .gif with a gradient vignette around the edges. When I publish from flash, there's a ton of banding going on. When I simply export with dithering on, it's really low quality.
Is it possible to have a high-quality gif with a gradient, or should I tell him its not possible and just send over a .swf?
The demand for a high-qulality GIF makes no sense.
Stilll, you can always go the route of making a true color gif:
If your client hates swf because of mobile reasons,
look into Cocos2D:
I personally prefer the Gif export settings in Photoshop. It gives you much more control over the export and gives you a preview as well. If there's no animation in your artwork, you can export a png image through File>Export>Export Image. If you want a transparency, select 32 bit, otherwise, 24 bit. Take the png into Photoshop, then choose File>Save For Web. It will bring up a dialog box where you can adjust settings until you're happy with how it looks. It even gives you a file size estimate which is often very helpful.
If you have animation in your artwork, you can export a quicktime movie instead, then bring that into Photoshop and use Save For Web and get the same options.