JPG achieves its impressive compression ratio at the expense of image quality. It was originally designed for continuous tone imagery where the compression artifacts were not likely to be noticed. TIF/LZW or TIF/ZIP won't match the file sizes of JPG, but also won't degrade the content (well, TIF/JPG will, but let's assume you avoid that subformat). GIF will sometimes work ok but only if your image has 256 colors or less (or the palette reduction isn't a problem which depends very much ont he source graphic, etc.) TIF (and to a limited extent GIF) support alpha channels too, although that probably isn't a consideration for this case.