There has been a few questions about layer masks recently, so here's a how to for you.
A layer mask lets you do lots of things, like blending one layer into another, masking the effects of, say, a filter on one layer, etc.
Here for the tutorial we have a background layer (blue) and another layer (yellow). This just makes it easier to see the effects. It could be two portraits your blending or whatever.
Step 1. When you have your second layer, open the layers palette (if it's not already open) and click on the yellow layer to make it active. Now click the Add layer mask icon on the palette (see picture 1, below).
Step 2. Now that you have the mask open - you won't see any difference. Why? Because the mask is white and that means that it's hiding the blue layer below.
Step 3. Click on the layer mask icon (the white mask rectangle) to make it active. Now, with a brush and black set as the color, paint on the image itself (not the mask). What you'll see is blue not black. That's because when you paint on black, it lets you see through the mask and see the blue layer below.
Step 4. Now, we understand roughly how it works we can go a step further, if we use the gradient tool set to black to white and drag it across the image, we get a lovely soft join between the top and bottom layers.
So, how can we use this? Well, suppose we have a model we want to add to a background. We open our background, drag the model photo on top, select the model for the existing background and with the selection open, click Add layer mask. Bingo! The background shows through and if we did a good job, it looks likes she's really there.
The beauty of the mask is that we can refine it as we go along. Paint on white to hide, paint on black to reveal and if we make a mistake, simply switch color and paint that bit back in. |