Adobe Photoshop CS3 - Manual (Page 325)

PHOTOSHOP CS3
User Guide
318
Masking layers
You can add a mask to a layer and use the mask to hide portions of the layer and reveal the layers below. Masking
layers is a valuable compositing technique for combining multiple photos into a single image or for making local
color and tonal corrections.
About layer and vector masks
You can use masks to hide portions of a layer and reveal portions of the layers below. You can create two types of
masks:
• Layer masks are resolution-dependent bitmap images that are edited with the painting or selection tools.
• Vector masks are resolution independent and are created with a pen or shape tool.
Layer and vector masks are nondestructive, which means you can go back and re-edit the masks later without losing
the pixels they hide.
In the Layers palette, both the layer and vector masks appear as an additional thumbnail to the right of the layer
thumbnail. For the layer mask, this thumbnail represents the grayscale channel that is created when you add the layer
mask. The vector mask thumbnail represents a path that clips out the contents of the layer.
Note: To create a layer or vector mask on the Background layer, first convert it to a regular layer (Layer > New > Layer
from Background).
Masking layer
A. Layer mask thumbnail B. Vector mask thumbnail C. Vector Mask Link icon D. Add Mask
You can edit a layer mask to add or subtract from the masked region. A layer mask is a grayscale image, so areas you
paint in black are hidden, areas you paint in white are visible, and areas you paint in shades of gray appear in various
levels of transparency.
Background painted with black; description card painted with gray; basket painted with white
A
B
C
D