Combine Selections

Combine Selections

By default, all masks are drawn in Add mode, meaning that
the contents of the mask are added to the layer selection,
and the area outside all of the masks is excluded. You can
set the mask mode to
. Add to mask contents to the image as a whole (Figure
3.16)
. Subtract to mask contents from displayed areas of the
image (Figure 3.17)
. Intersect to mask contents to show only areas overlapping
with masks higher in the stack (Figure 3.18)
. Difference to mask contents to hide areas overlapping
with masks higher in the stack (Figure 3.19)
. None to disable the mask (Figure 3.20)
The Inverted toggle next to Mask Mode menu combined
with Add causes the areas outside the mask to be added;
combined with Subtract causes the areas outside the mask
to be subtracted, and so on.
The Mask Opacity property (M) attenuates the strength of a
mask; setting any mask other than the fi rst one to 0% is like
disabling it. This control works differently for the fi rst (top)
mask. A single Add mask set to 0% Mask Opacity causes the
entire layer to disappear, inside or outside the mask.
However, if you set the fi rst mask to Subtract, and Mask
Opacity to 50%, it does just that—instead of the area inside
the mask reappearing, the rest of the scene becomes 50%

transparent, just as with Add > Inverted. If you want this
to behave as it should, set the fi rst mask full-frame to Add
mode (just double-click the rectangle mask), then add the
Subtract mask as the second (or later).
To keep multiple masks organized
. Enable Preferences > User Interface Color > Cycle
Mask Colors to assign a unique color to each new mask
. Press the Return key with mask selected, then type in a
unique name
. Click Mask Color swatch (to the left of the name) to
make it more visible or unique
. Context-click > Mask > Locked, Mask > Lock Other
Masks, or Mask > Hide Locked Masks to keep masks
you no longer wish to edit out of your way