For those that might have more time to work on the PIL source than myself, there's a semi-official set of PNG test images at: http://www.schaik.com/pngsuite/pngsuite.html A quick check shows that PIL's PNG support passes 125 of the 157 test cases. -Steve P. -- Steve Purcell | Stunt Programmer steve@websentric.com | WebSentric Software GmbH