Settings - Overlay - Main tab (Shaped Masks)
Use this method to create a simple overlay. For example, you can create a rectangular or round overlay, and add soft edges and outlines. You can use the zoom and positioning controls to place the overlay in the location of your choice on the image.
n Rectangle: Select this for a rectangular shaped mask.
n Circle: Select this for a rectangular shaped mask.
n Edge Softness: Use this slider, or click Plus (+) or Minus (-) to increase or decrease the degree of blurring of the edges.
n Outline: Choose the type of outline for the mask, or choose to not have a frame for the mask.