When you promote or paste a selection to create a layer, some of the pixels surrounding the selection border are included, especially when the selection is anti-aliased or feathered. The Layers > Matting commands clean up the border by removing these pixels.
There are three Matting commands: Remove Black Matte, Remove White Matte, and Defringe. Use the Remove Black Matte or Remove White Matte command when the selection came from an image with a black or white background. These commands remove the black or white pixels at the layer edges. Note: To clean up the edges of a selection before you promote or copy it, use the Selections > Matting command, see Cleaning Up the Edges of a Selection.
Use the Defringe command when the selection came from an image with a colored background. Defringing bleeds non-feathered pixels in the layer edges outward and over the “jaggies” in the feathered part of the layer.
Important: This command works on 16 million color and greyscale images only. To increase the color depth of an image, see Increasing the Color Depth of an Image.
To use a Matting command:
On the Layer palette, click the name of the layer that was created from a selection.
Do one of the following:
To remove the black matte, choose Layers > Matting > Remove Black Matte.
To remove the white matte, choose Layers > Matting > Remove White Matte.
To remove a colored matte, choose Layers > Matting > Defringe to open the Defringe dialog. Enter the number of pixels to defringe and press Enter.
Arranging the Stacking Order of Layers
Moving Layers within the Image Canvas
Deleting Layers or their Contents