A “Session File” is a file that is designed to save the current stateof ones work including all parameter settings, user preferences, machine andmaterial info, as well as the source image. One of PhotoGrav’s primary design concepts is thenotion of a “ PhotoGrav Session” and its respective “Session File”(*.pgs).

It is especially recommended to become familiar with these primaryfunctional blocks located on the Primary Toolbar and the respective operationssince these are vital in producing a digital image for laser engraving. The description withappropriate graphics include: (1) PhotoGrav Sessions, (2) The PrimaryToolbar and its operations, (3) Viewing Panes and Panels, (4) Interactive Mode,(5) Cloning-Comparison of Results, (6) Machine Selection, and (7) AutomaticUpdates. This chapter, Chapter Three, provides a detailed description of each ofthose primary functional blocks as well as describing a PhotoGrav Sessionand the essentials of the PhotoGrav Application. Chapter Two described PhotoGrav’s operationaloverview and how PhotoGrav uses these to provide a smooth flow of eventswithin a PhotoGravSession.