Use Revert To to return to a previous version of your design.
Create a drawing using the Draw and Insert features.
Choose File > Save (or press ⌘S) to save the design. See Save.
Change the design.
Choose File > Save (or press ⌘S) to save the design again.
Choose File > Revert To. All of the changes that you have made and saved can be selected on the screen.
Click Restore to go back to an older version, or Done to return without reverting,