Exhaustive PNG informational resource by the developers of ImageOptim: PNG that works.
About George Coghill
Cartoonist, artist and illustrator specializing in vector art cartoon logos & cartoon character design. George is also a huge Mac geek and the founder of The Apple Artist blog and podcast.
[blog] More Info About The PNG Format Than You Can Possibly Imagine http://t.co/ERe1G7m8 #Tips #fileformat #graphics