Different Types of Blend Modes
With the blend modes in Photoshop C6, you can “combine” layers in new and interesting ways. I use the term “combine” here loosely, because you’re not really merging or performing any type of destructive editing processes on the individual layers. You can always get your original layers back by changing the blend mode back to normal.
You can access blend modes several different ways in Photoshop, but the easiest method is to use the drop-down list found in the Layers panel. Referring to the diagram shown to the right, if you want to blend Layer 1 with Layer 2, you would select Layer 1 and then choose the blend mode you want to use.
There are a lot of calculations that go on behind the scenes when determining the result of a blend mode application. For instance, after looking at the color information in each channel, the Multiply blend mode multiples the base color by the blend color to come up with the result color.
Rather than try to memorize the technical definition of each blend mode, I recommend experimenting instead. Try each of the different blend modes on any pair of layers and see what type of result you get. Even those who are experts at manipulating blend modes often resort to this type of experimentation in order to get the exact look they want to achieve.