File with a .PSB extension contains an image of a size greater than the standard size (in pixels), created in Adobe Photoshop. In this format, am image larger than 30 000 x 30 000 pixels and not larger than 300 000 x 300 000 pixels can be stored.

A function of operating on larger files in the PSB format and storing them has to be enabled in the program options in the Preferences window.