How to Use Layer Mask Gradient and Brush Tools in Photoshop CS6
Layer masks in Photoshop CS6 allow you to gradually brush in transparency and opacity on a selective pixel basis. Two of the layer masking tools — Gradient and Brush tools — are more commonly used than the others:
The Gradient tool: Setting this tool to a linear gradient of black to white or white to black is truly awesome. Select the layer mask in the Layers panel and drag with the Gradient tool on the layer mask to create the gradient. The darker areas of the gradient gradually hide the image, whereas the lighter areas gradually show the image.
The Brush tool: With a large, feathered tip, using the Airbrush option and the Flow set to around 10%, this tool is amazing. With these settings in place, you can create feathered edges that blend one layer into another without any harsh lines. Again, select the layer mask in the Layers panel and drag with Brush tool on the layer mask.
In the example, which is an image with two layers (the flag on the bottom and the girl on top), combine these tools to create the best combined image. Start with the black-to-white linear gradient, dragging it from the right edge of the image through to the left edge.
Then take the Brush tool with a large feathered tip (150 pixels), selected the Airbrush option, set the Flow to 10%, set the foreground color to black, and work your way around the profile of the girl’s face to get rid of some more of the background behind her. Then refine the edge a little more with a smaller brush of 75 pixels and an opacity of 50%.
To edit a layer mask, click the Layer Mask thumbnail in the Layers panel. Select your desired painting or editing tool, and paint or edit the mask to perfection. Just be sure that you’re working on the layer mask, rather than editing the image itself. Otherwise, you apply paint directly to your image.
You can tell you’re working on the layer mask when you see brackets around the layer mask thumbnail in the Layers panel. You also see the Layer Mask icon highlighted and the mask thumbnail displayed in the Properties panel.