What is a .PNG File?

PNG or Portable Network Graphics is a file format that was designed to replace GIF. Not only is GIF a technically limited file format but LZW, the compression algorithm it uses, is owned by Unisys who are more than happy to charge for the privilege of using it. PNG is patent-free and offers enough features to also make it an valid alternative to the TIFF file format in some cases. The file format is meant to store bitmap data. PNG was developed around 1995 by an Internet working group led by Thomas Boutell. Its popularity got a big boost when W3C, the organisation that defines web standards, started promoting its use in 1996. Major graphic arts applications such as Photoshop and InDesign fully support PNG, although the file format isn’t that popular in prepress because it doesn’t support CMYK. I often use InDesign to create presentations and for this type of application, PNG can be very useful.