Great article of 456bereastreet.com how to create a button. He uses a lot of code, but the result is perfect!
A successfull bulletproof image-based button should:
- Automatically grow horizontally to fit any amount of text
- Grow horizontally and vertically if text size is increased or if the text wraps to multiple lines
- Retain its appearance within reasonable limits
- Be able to have rounded (or other non-square) corners
- Have no unclickable areas
- Be readable when images are disabled