IE6 Support with PunyPNG
If you need to support IE6 browsers with PNGs produced with PunyPNG, please be sure to use Diller Design’s awesome dd_belatedpng plugin to ensure compatibility. I tried using other “png hacks” like Supersleight, which was attractive because it came as a jQuery plugin. However, Supersleight and others all use Microsoft’s AlphaImageLoader to load transparent PNGs. Not only are their memory issues and crop issues involved with using the AlphaImageLoader, that technique does not work with the PNGs that PunyPNG produces. Using the Dirty Transparency technique, PunyPNG produces 8-bit transparent indexed PNGs and it’s the indexed part that AlphaImageLoader chokes and shows nothing. Pretty bad.
Thankfully, the dd_belatedpng plugin takes a different approach, using Microsoft’s VML implementation to avoid memory issues and as a bonus, supports transparent indexed PNGs. There is finally a use for VML!
Use IE6 to and view this browser test that I created comparing using and not using dd_belatedpng:
