User Guide

Corel Painter 255
Working with Layer Masks
You can create a layer mask to define
what areas of a layer are visible in the
document window.
Masking originated as a technique for
creating color separations, where
sheets of masking material were hand-
cut to define the color regions in an
image. In the Corel Painter digital
workspace, the layer mask is a
powerful tool for controlling image
composition and effects.
Layer Masks vs. Channels
A layer mask is similar to an alpha
channel. Both are grayscale images
that you can create and edit. Although
the Channels palette provides access
to both channels and layer masks,
their characteristics and functions are
different:
• The canvas can have up to 32
alpha channels; each layer can
have at most one layer mask.
• Channels don’t influence the
visibility of the canvas image; a
layer mask defines what areas of a
layer’s image are visible.
• An alpha channel, when loaded,
protects designated areas of an
image; a layer mask does not
provide protection.
• A channel is enabled by loading it
to a selection; a layer mask can be
enabled and disabled at any time.
For more information about channels,
refer to “Understanding Alpha
Channels” on page 219.
Creating Layer Masks
A layer mask is a grayscale image.
Where the mask is white, the layer
content is visible; where the mask is
black, the layer is transparent,
revealing the imagery below it.
Intermediate levels of gray are
partially transparent.
You can create a new, blank layer
mask, or you can create a layer mask
based on the layer’s transparency. A
layer mask based on transparency is
white wherever the layer has content,
and black in other areas. For more
information about layer transparency,
refer to “Preserving Layer
Transparency” on page 241.
You can also copy a channel to a layer
mask.
A layer mask for the butterfly layer is created
based on its transparency. Black areas are
transparent; white areas reveal the image.
To create a new, blank layer mask:
1 Select a layer.
2 Do one of the following: