I use EM as well, I should have been more specific, I didn’t want this to be an em vs px debate. What I am really curious to find out is, how much adjusting do you find yourself doing as your layout breaks down? Are you adjusting font size a lot? Is it typically only headers that need adjusting? If you’re using the method of just increasing the body font-size percentage, how do you typically determine the percentage increase? Is it completely arbitrary or is there an equation you use?