vol7ron - 10:39 pm on Mar 4, 2008 (gmt 0)
...you would have to allow for text resizing and that a part of another part of the sprite/image won't overlap into anothers space...
That is important to remember, but in terms of borders and corners and buttons that should not be affected by font sizes, this shouldn't matter. Even when pages are zoomed in/out or the browser's text size is changed. This is why you see certain images very close together. None of these images are backgrounds with a text overlay.
Because of the way GIF compression works, repeated pixels of the same color (in this case white), especially on the horizontal axis
Thanks for the lesson on GIFs, but this is a PNG image, which although it too has a great compression, it is lossless. Your point is still valid and will apply in this case, but you shouldn't use the GIF as an example when talking about PNGs, the compression would be much higher because bits are being lost in the process.