A PlanetPress Document Package, or PTZ, is a file format consisting of a ZIP file, which contains all the document's data and resources. With a PTZ, resources are extracted and uncompressed only once when the PlanetPress Suite Workflow Tool receives the file. All the resource files are stored in a sub-folder from where they are used as needed by the PlanetPress Suite Workflow Tool, and a smaller PTK file is placed in the Documents folder.