Autograph supports an internal format for saving and loading
drawings. Files are loaded with the <Files>:<Load atg> menu button,
and saved with <Files>:<atg Format>.

The first time you save a drawing, Autograph prompts a dialog window
where you can edit the filename using the Backspace and Delete keys.
Just click with the mouse cursor in the edition area, then type the
file name with or without its .atg extension. The DEL keyboard key
will erase any string in this area being selected by the
window-manager drag.