title: enhancing image quality for iphone 4 from 72ppi to 326ppi
body: <p>I have been trying to understand how to enhance the button quality of my mobile design. My navigation buttons are currently a png sprite that is 72ppi then I have a copy of these buttons in 326 ppi. I have read that iphone4 can automatically pick up the 326ppi image by adding @x2 to the current navigation sprite? At the moment I'm just a little confused about the process and how my current navigation sprite of 194x343px @ 72ppi can change into an image 335x1469px @ 326ppi?</p>
  
  <p>If anyone can provide some useful info and guidance that would be great.</p>
  
  <p>Kyle</p>