The Feather command feathers the edges of the selection. This creates a smooth transition between the selection and its surroundings. You normally feather selection borders with the “Feather Edges” option of the selection tools, but you may feather them again with this command.

7.9.2.  Description of the “Feather Selection” dialog window

Figure 10.39.  The “Feather Selection” dialog

Feather selection by

Enter the width of the selection border feathering. The default units are pixels, but you can also choose other units with the drop-down menu.