Today’s Question: Is there a way to flip a selection in Photoshop?
Tim’s Quick Answer: Yes, of course. You can both invert and flip a selection, using the Inverse command if you want to invert the selection, or the various Transform commands to flip the selection horizontally or vertically.
More Detail: If you want to invert a selection so that the deselected area is selected and vice versa, you can choose Select > Inverse from the menu. This will reverse the selection so that you have the opposite of the original selection.
Before using the general Transform commands to change a selection, first you need to put the selection itself into “transform” mode. To do so, with an active selection choose Select > Transform Selection from the menu. You can then use the various Transform commands on the Edit menu to actually transform the shape of the selection.
If you want to flip a selection horizontally or vertically, you can use the Transform commands. For example, you can choose Edit > Transform from the menu, and then choose Flip Horizontal or Flip Vertical from that submenu based on the direction you want to flip the selection.
There are also a wide variety of other commands available on the Edit > Transform submenu, which can also be used to manipulate the shape of a selection. You can also access the equivalent of the Free Transform command by choosing Select > Transform Selection from the menu.
It is also worth noting that if you have used a selection as the basis of a layer mask, you can also apply the Transform commands (among other commands) to change the shape of the layer mask.