Use the Mask Create from Selection command to build a Mask using the current selection area. Like painter's masking tape, a masked area will protect a picture from unwanted paint and other modifications. Only the areas lying outside the mask may be modified. Once enabled, a mask will remain in effect until removed using the Mask Delete command or the picture is closed.
The Mask Invert command inverts the current masking area. The original masked area is unmasked and the area previously outside the mask boundary becomes the new mask.
The Mask Load from File command allows you to create a mask using a disk-based mask (*.NPM) or other compatible image file. The file is loaded and converted to grayscale (if needed). Black areas of the image become the protected portion of the mask, while white areas will be unmasked, allowing painting and other modifications to occur. The new mask is enabled and placed on top of the active picture. The mask will remain active until removed using the Remove/Clear command or the picture is closed.
The Mask Save As command allows you to save the active mask to disk in a special mask (*.NPM) file format. Once saved, the mask file may be loaded into the same or another picture using the Load from File command.
The Mask Remove/Clear command removes the current mask from the active picture.