A layer’s opacity determines the degree to which it obscures or reveals the layer beneath it. A layer with 1% opacity is nearly transparent, while a layer with 100% opacity is opaque. Transparent areas remain transparent regardless of the opacity setting.
You use layer blending modes to determine how a layer blends with the pixels in layers beneath it. Using blending modes, you can create various special effects.
A layer’s opacity and blending mode interact with the opacity and blending mode of painting tools. For example, a layer uses Dissolve mode at 50% opacity. You paint on this layer with the Paintbrush tool set to Normal mode at 100% opacity. The paint appears in Dissolve mode at 50% opacity. Similarly, if a layer uses Normal mode at 100% opacity, and you use the Eraser tool at 50% opacity, only 50% of the paint disappears from the layer as you erase.
A. Bamboo layer and Borders layer B. Bamboo layer with 100% opacity and Color Burn mode C. Bamboo layer with 50% opacity and Color Burn mode
(Windows) Immediately after you choose a blending mode, you can press the up or down arrows on your keyboard to try other blending mode options in the menu.
You can quickly select all the opaque areas in a layer. This procedure is useful when you want to exclude transparent areas from a selection.
The checkerboard grid identifies transparency in a layer. You can change the appearance of this grid; however, do not change it to solid white because you’ll eliminate the visual distinction between opaque (white) and transparent (checkerboard).