Blending Options

One other way to combine image layers is to apply the Blending Options available in the Layer Style dialog box. These options allow you to create transparent areas in a selected image layer based on how bright or dark the image is. To access the blending options, double-click the area next to a selected layer’s name in the Layers palette. This launches the Layer Style dialog box with the Blending Options panel displayed. At the bottom of the dialog are two sets of sliders; one labeled This Layer and another labeled Underlying Layer. The This Layer slider makes areas of the active layer disappear. The Underlying Layer slider reveals image areas from all underlying layers.

“This Layer” Sliders As you move the left This Layer slider toward the center of the black-towhite gradient bar, Photoshop hides all those shades of gray in the image that are now to the left of the slider. The closer to the center you drag, the more dark areas  you drop in the active image layer. Moving the right This Layer slider toward the center makes the bright areas to the right of the slider disappear. This can be especially useful for catalog designers attempting to drop a white background on a product shot—provided the image doesn’t contain any white areas, such as a ring, or any other shiny metal surfaces. This can eliminate the need for making selections or drawing clipping paths.

With the exception of dropping white backgrounds, the only problem with the blending sliders is that as you move them to drop dark or light areas, the remaining pixels contain crisp, hard edges. To create a transparent blend, you must Option/Alt+click the sliders and drag. This splits the slider into two halves. You can then control the opacity amount of the blend by moving the halves of the slider. The farther apart you make them, the smoother the blend.

“Underlying Layer” Sliders The Underlying Layer sliders work the same as the This Layer sliders, except as applied to all of the layers below the active layer in the Layers palette. As you drag the left and right Underlying Layer sliders closer to the center, more and more of the underlying image areas are revealed. Option/Alt+click and drag to split the sliders in two and create a transparent blend.

Alot of times when I’m creating collage pieces for print materials such as brochures, advertisements, book covers, or magazine layouts, I use layer style blending options along with a gradient layer mask. This allows for more control when combining specific image areas of a composite graphic.