Quote Originally Posted by Midgardsormr View Post
Fingolwyn, I recommend .png rather than .bmp, especially for a style like TSR Blue. PNG uses lossless compression, so no data loss, it will be way smaller than a bmp, and it displays in more software.

For more information, reference this old thread: Image Export Formats.
I use an archaic program (DungeonCrafter v1.4.1), the output of which (and working form) is .BMP. I could convert to .PNG instead of .JPG though. I always send the original output file in case the recipient wants to do anything with it.