Hi Lostboy! A mask is the inverse of a selection in Photoshop, anyway. But bear in mind a mask doesn't do anything in itself, it just lets you operate on selected parts of an image (or to look at it the other way, it protects parts of the image from what you are doing.) Anyway, load the selection, then use Select, Inverse to change the selected to a mask if you want. CTRL H (Apple H) toggles the marching ants on and off if they are in the way. Bear in mind th emarching ants indicate 50% or more selected, but a pixel can have the full range of 0 to 100% selected (or masked)