solid border on bases?

Hey everyone! I'm an icon maker, lately I've been making mostly bases. This question goes out to the icon makers, as well as icon takers. Do you prefer bases to have a solid black 1 pixel border, or no? When you're creating a customized icon out of someone's base, does the border just get in the way? or do you think it enhances the picture? Please comment & let me know. All opinions are welcome & very much appreciated. Thanks!