FAB 3000 has two specific commands for this requirement.
Automatic: FAB 3000 will attempt to automatically detect the PCB border boundary and create a border layer.
Go to menu: Fabrication / Detect Border (Automatic)
Selective: Select one edge of the PCB border and FAB 3000 will attempt to close it. Should FAB 3000 get stuck it will prompt you to select the next edge (until it closes). A border layer will be created upon completion.
Go to menu: Fabrication / Detect Border (Selective)
Numerical Support Team
Automatic: FAB 3000 will attempt to automatically detect the PCB border boundary and create a border layer.
Selective: Select one edge of the PCB border and FAB 3000 will attempt to close it. Should FAB 3000 get stuck it will prompt you to select the next edge (until it closes). A border layer will be created upon completion.
Go to menu: Fabrication / Detect Border (Selective)