Just a small addition. Yep, for best results, BMP or TIFF. Even at minimum compression (maximum quality with virtually no discernible quality drop) JPG will give quite a substantial saving in file size, if that is important. Do remember though that JPG compression is multiplicative. What I mean by that is that if you save a JPG at 70% quality, then open it for editing postwork and save it again at 70% quality, you will further downgrade the final quality to 70% of 70% - i.e. 64%, and this degradation will continue to accumulate each time you save the file. So I normally do all my editing using a lossless format like BMP or PSP, only converting to JPG when I'm sure I have the final version ready for the web. When setting the compression level, it's useful if you can preview the results so you can create an optimum balance between file size and quality of output. Paint Shop Pro, Fireworks and doubtless many others, do offer this facility, or failing that you can download utilities from the web to do it as a separate process.