Photo Jumble Project file icon

Photo Jumble Project file (*.pjproj) is a proprietary Photo Jumble file format. It can be opened with Photo Jumble only. When collage saved into .pjproj file you may later open and continue to edit it. To save collage into common used graphic file format please use Export Image to File menu option.
Photo Jumble Library file icon

Photo Jumble library file contains essential information about image files that will be used for mosaic collages. This info includes file name and location, image sizes, colours, colour distribution and so on. Also it contains a small thumb preview of every tile image. These thumbs are used for fast screen previews.

When the program exports collage into image file it use to draw re-scaled versions of your original images. That's why it is important to keep your original image files in the same place as they were when you build the library.

Photo Jumble may work with image libraries generated by Photo Jumble itself (they have .pjlib file extensions) and with libraries build with Image Mosaic Program Mazaika (these files have .mzlib  file extensions). Please see how to make library here.

The difference between .pjlib  and .mzlib:
Photo Jumble Libraries keep information about transparency of tiles and can be used for creating non-rectangular mosaic and collages. Mazaika Libraries don't respect transparency.