About Bitmap Masks - MACROMEDIA FIREWORKS 8-USING FIREWORKS Use Manual

About bitmap masks

If you're a Photoshop user, you may be familiar with layer masks. Fireworks bitmap masks are
similar to layer masks in that the pixels of a mask object affect the visibility of underlying
objects. However, Fireworks bitmap masks are much more versatile: you can easily change
how they are applied, whether using their grayscale appearance or their own transparency. In
addition, the Fireworks Property inspector makes mask properties and bitmap tool options
more readily available, greatly simplifying the mask-editing process. When a mask is selected,
the Property inspector displays a variety of properties not only for a selected mask but also for
any bitmap tools you might use to edit the mask.
Original objects and a bitmap mask applied using its grayscale appearance
You can apply bitmap masks in two ways:
Using an existing object to mask other objects. This technique is similar to applying a
vector mask.
Creating what's known as an empty mask. Empty masks start out as either totally
transparent or totally opaque. A transparent (or white) mask shows the masked object in
its entirety, and an opaque (or black) mask hides the masked object completely. You can
use the bitmap tools to draw on or modify the mask object, revealing or hiding the
underlying masked objects.
212 Chapter 9: Layers, Masking, and Blending