5

If you’ve used a Spill Suppressor filter, don’t delete it, because it’s probably changing the
color of the subject.
5 Feather the edge of the holdout mask you’ve just created, to make sure that it blends in
with the object you initially keyed.
In the following image, the mask on the bird creates a clean key by removing the “dirt”
left by the original key.
6 As an optional step, you can nest the originally keyed layer and the holdout matte you
just created inside a dedicated group so you can manipulate the entire subject as a single
object.
Applying Multiple Keys to a Single Subject
In some instances, it may be difficult to key an entire subject with a single keying filter
while retaining fine details. For example, uneven lighting or background color might
mean that the best settings to key a subject’s hair may not work elsewhere. In such cases,
you can use masks to isolate different parts of a subject, and then apply different keying
settings to each area.
To segment a subject into separate keying zones
1 Create a group and place the layer you’re keying in the new group.
2 Duplicate the layer you’re keying until you have a separate duplicate for each part of the
image you want to key separately.
3 Use a mask tool to mask each part of the subject in the duplicate layers.
Make sure the duplicate layers overlap, so there are no gaps in the foreground.
Note: You might need to animate the overlapping masks if the foreground subject is
moving.
4 Apply the relevant keying filter to the isolated parts of the subject, the adjust each filter’s
settings.
1223Chapter 20 Using Shapes, Masks, and Paint Strokes