I’ve talked a lot about “masking this off” or using a “Layer mask” in Photoshop with the assumption that everybody knew how to use them. And that was a bad assumption on my part. So I’m going to do a quick little tutorial on layers masks and how to make and use them.
When we place a layer onto an image in Photoshop, it can be many things, it can be an “Adjustment Layer” where you made a specific adjustment to an image, Levels Curves, Saturation etc and applied it to an image but as a separate layer so not to change or damage the original image and make those changes reversible.
We could also add a texture layer, a color or gradiant layer a text layer, we can even put a whole photograph on top of another in a layer as we would do in a “Blend” as I showed here.
Now a layer, in most cases is a solid object above the layer below. But what if we wanted to show some of the layer below this layer? Well we could just use the eraser tool to erase away the top layer. But the problem with that is once you erase away that area is gone unless you step back in your history. Erasing is very hard to fine tune. “Oops went to far can I put some back?” No you can’t. So instead we use a layer Mask, which allows us that flexibility of taking away, putting back, feathering and varying opacity.
So let’s make a practice sample so we can easily see how to use layer masks.
Start in Photoshop and go to File> New and let’s make a new image. We’ll make it easy and use one of the presets and make an 800 x 600 image. You don’t need to worry much about anything about this new image except for the size. Most likely you will now have an 800x 600 white image on your screen now. If you have a different color or even a transparent one that’s OK we’ll fix that in the next step
Now go to your tools and select the Paint Bucket Tool, then go to the color palette and click on the foreground color. Choose any color you like but to make this more visual choose something other than Black or white. In my case I chose full red. Fill your image using the paint bucket tool with red
Now go to Layer> New and add a layer on top of the red layer. Once again go back to your paint bucket tool and now choose a different color. In my case I chose full Blue and fill the next layer with a different color.
You should now have two layers and your layers should look like this.
Now at the bottom of your layer palate you will see an Rectangle with a white circle in it and if you hover over it, it will say “Add Layer mask” click that and it will add a layer mask to your top layer. You should now see a white box next to the blue box in your layers panel, The White box is your layers mask.
Now let’s go back to our color palette and return them to the default values by pressing “D” on our keyboard. Make Black your color ( you can swap easily between white and black by pressing “X”) And grab your brush tool set to a size 200 soft brush and with black as your color, take a swipe across the Blue layer (making sure the White layer mask is highlighted ion your layer panel). What happened? You now see the red layer below.
By painting black on that layer mask, you “revealed” the layer below. Here s the most important part to take away from this: White Conceals, Black Reveals, the layer below.
Now switch your color back to white (x) and paint back over it. It conceals the red layer below in as little or as much as you want.
Now this may also be a very good time to get to understand Brush “Hardness” hardness is how hard or soft the edge of the brush is. Soft would give you a very diffuse edge; Hard would give you a very defined edge. So with your one swipe across, below that change your brush hardness to 100 (by clicking the downward arrow next to your brush size) and take another swipe across your image with black. See the difference in the edge?
So that is the basics of using a mask. Most times I use a Soft brush so there is a smooth transition between what I want to show and what to conceal but there will be times you need to use a hard edge to clearly define what you want to show, such as cutting out an object.
But wait, what if I want to go somewhere in between? I want to show the layer below but not fully or I want to apply just a little of the effect layer in some parts and it fully in others?
There are two ways to accomplish that. The first is to vary the opacity and fill of the brush. Here is a swipe across using 50% Opacity and full on the brush. You can see that if only partially shows the layer below in fact it turns the swipe purple with the mix of red and blue.
But that’s not my favorite way of doing this even though it may be the preferred method of Photoshop Professionals.
If White Conceals and Black Reveals, Then what would a shade of gray do? Exactly!
When I want to vary the amount of the layer below to show through I use varying shades of gray to paint over and accomplish this. It gives men great control and is quickly and easily done. The lighter the shade of gray, the less will show through, the closer to black the more that will be revealed. Choosing middle gray accomplished the same thing that the other method above did.
Just to re-emphasis something I said earlier: If at any point you get White or Black paint instead of just masking on your image. Make sure that the Layer Mask is selected on the Layer Palatte
And that is using layers mask, short and sweet.
Hope that Helps,