Other Photoshop Masking Options- Layer Masks
and Clipping Groups
Photoshop also lets you mask off portions of layers, letting the lower layers
show through. Using a layer mask has the same effect as erasing the upper
layer, except that you can always go back and modify the mask further…you
don't loose the area that would have been erased. If you're in the experimental
stages of working with montage and transparency, layer masks can be very useful.
You should be careful though…layer masks can increase file size dramatically,
especially if you use more than one or two at a time.
Follow the procedure below to create and remove a layer mask.
- In the layers palette, click on the
layer to be masked. It will highlight to show it is active.
- Click on the mask icon at the
bottom of the layers palette to activate the layer mask. When you do this,
a second white thumbnail representing the layer mask appears in the layer
tile, next to the thumbnail of the image itself.
- The color swatches revert to grayscale at this point, just as they did
with the Quickmask process. This is because layer masks operate on grayscale
values just as the Quickmask feature does. You can paint with black to hide
areas, or paint with white to reveal them. As before, painting with shades
of gray applies a transparent mask. In
this case, I'll paint with black to hide the background.
- When you are certain that the mask is just as you want it, you can drag
the mask thumbnail into the small trash icon in the layer palette. This
will launch a dialog box that asks
if you want to apply the mask before discarding the mask. Click OK if you
wish to do this, and Photoshop will delete the masked area out of the layer.
Another layer masking option is to use what Adobe calls Clipping Groups.
A Clipping group uses a layer as a mask, framing the layers above it.
The base layer in a group acts like a window that the upper layers can
be seen through. Follow the steps below to create a clipping group:
- In the layers palette, determine which layer will serve as the base layer
and drag it below the other layers.
- Hold down the Option/Alt key and position
the cursor on the border between the base layer and the one above it.
It will change to the clipping group symbol when positioned properly. Click
to add the above layer to the clipping group.
- Repeat step to for any other layers that should be added to the group.
Remember that all layers in a group must follow each other sequentially,
so plan accordingly.
The final result is that the
upper layers only show through the mask created by the base layer.
fin.
URL: http://www.webreference.com/graphics/
Created: Nov. 16, 1998
Revised: Nov. 10, 1998
