To truly experience the power of Adobe Photoshop, you have to become comfortable with layer masks. It's a critical step in image manipulation. Layer masks are greyscale images that control the level of transparency in your image if applied to it. In this article, you will learn how to understand layer masks in Photoshop step-by-step.

This tutorial is suitable for all skill levels. General knowledge of the basic tools in the program is helpful. You should be able to complete it in 10 to 15 minutes. Although the examples are created in Photoshop, most of the methods are valid for other image editors on the market today. Below you will see how to create and delete masks as well as use them.

You can use any shape to make a selection including type. In the example, we will use a simple test image to illustrate the effect.

1. Create a new document by typing Ctrl+N.
2. Set the width and height to 500 pixels and give the file a transparent background.
3. Name the transparent layer background.
4. Use Shift + Ctrl + N to add a new layer. Name it testImage and fill it with the color red.
5. With testImage active, make your foreground and background colors white and black. Go to Filter -> Render -> Clouds. Now, you have your sample picture.
6. Activate the rectangular marquee tool by pushing M. Draw a medium sized box in the middle of the window. This is the selection of the area you want to keep.
7. Keep the selection active and push the mask icon. (It's at the bottom of the layer interface and looks like a square with a circle in the middle.)

Some times you will need to add or remove sections of a mask. Remember that it responds to shades of grey, black and white. Black areas will be fully transparent while white ones will be completely opaque. Any shades between will vary in transparency. To see this in action, you will add a gradient to your previous mask.

1. On testImage, hold down 'Alt then click the mask thumbnail. Now, you will see just the mask in your image window.
2. Draw a circle in the middle of your white box.
3. Using the gradient tool, fill the circle. This tool can be accessed with the shortcut G.
4. Bring back your actual picture by selecting its image thumbnail on the layer.

There are a multitude of helpful uses for this type of mask.

• Hiding Unwanted Areas: Instead of deleting a part of a picture you don't want, use a mask to hide it. This is more efficient because if you change your mind later, you can easily go back to the original.

• Transparency Blending: You can use a gradient or various shades of grey paint on the mask to blend one image with another.

• Blend Modes: If you need to only apply a blend mode effect to one part of your graphic, make a selection around it and mask it. Then, you can just duplicate the original and place it behind the masked out layer. (Create the duplicate before making the mask.)

• Adjustment Layers: Add your adjustment layer then make a mask for it using the normal procedure. This way the adjustment only happens to the parts valid in the mask.

• Tinting: If you wanted to color one section of a picture red, you could combine a red layer with a mask of that shape to accomplish it.

• Feathering: With the mask active, contract your selection using Select -> Modify -> Contract. Then, use Select -> Feather and push the mask icon.

• Depth of Field: This is a property of real photography when using different focal lengths. You can mimic it with masks and blurring.

1. Duplicate your photograph then blur it.
2. Once again, duplicate your unaltered background and use a mask with a black to white gradient in it. The black portion should point towards the area farthest away.
3. Now, place your foreground graphic on the topmost layer. If your foreground is actually part of the background, use a copy of its unaltered version and mask only the focal image.

The easiest part of the process is deleting masks. Basically, you just drag and drop to remove it.

1. Select the mask thumbnail on the testImage layer.
2. Then, use your mouse to grab it and drag it to the trash can icon at the bottom right corner of the layer window.
3. If you want to make the cut out permanent, choose apply. However, if you want to get rid of the mask without changing the image, choose discard.