QuickFlip works by using an animation shortcut that is barely noticeable when flipped quickly (hence the name). This shortcut improves performance while allowing the flip effect to work smoothly with any piece of markup regardless of images, backgrounds or CSS.
It provides an attractive alternative to other slower and more resource heavy Flash and jQuery flip animations. However if you want a smoother option with a depth effect try jQuery Flip!, although this only works with background colors (not images) and hides the panel content before flipping.
