Home » Tip of The Day » Undo and Step BackwardUndo and Step Backward February 12, 2016. Posted in: Tip Of The Day. To undo, simply press Ctrl (Mac: Command) Z. To do multiple Undos (Step Backward) press Ctrl (Mac: Command) Alt (Mac: Option) Z. « Previous Photoshop Tip: | Next Photoshop Tip: » Sign-up for the PTC Newsletter so that you'll never miss a tutorial!. Your Email Address: