What are Photoshop blending modes and what do they do? Each layer of visual information in a Photoshop file doesn’t have to completely obscure the layer below. Photoshop layers can instead be set to blend with layers beneath – a useful way to create some interesting effects.
In a standard 8bit RGB image, each pixel has a colour value between 0 and 255 (with 0 being black and 255 white). When blending layers together, Photoshop checks the colour value of each pixel on a layer, and combines it with the value of the pixel in the same position on the layer beneath. The blend modes control the different ways these two values are combined to produce a new pixel colour value.
Normal & Dissolve Blends:
The normal setting means that the layer does not blend at all with those beneath, while Dissolve blends pixels with the layer below on a random basis (which tends to produce a speckled, sharp mix).
Multiply Blend:
This is the mix I use most often, and is probably the easiest to understand. Photoshop combines each pixel’s colour value with that of the pixel beneath in an effect similar to overlaying coloured sheets of transparent plastic. eg: a cyan layer multiplied over a yellow one will produce green. note: black (0) remains unchanged, while white (255) will disapear.
Darken & Darker color Blends:
Here, the former mode blends values only if the pixel below is lighter than the one above, while the later uses the darkest value from each layer.
Color Burn & Linear Burn Blends:
With these blends, Photoshop exagerates the contrast and brightness levels between colour values in the layers. Can yield unexpectedly useless/fantastic results, so it is often worth applying to see what happens.
Lighten Blend:
Photoshop compares the two pixel values, and the lower value is ignored in favour of the higher, resulting in a lighter image.
Screen Blend:
The precise reverse of the Multiply blend.
Color Dodge & Linear Dodge Blends:
These blends have the opposite effect to Color Burn and Linear Burn.
Lighter Color Blend:
Similar to the Lighten blend, but tends to produce more pleasing results due to a slightly different pixel selection method.
Overlay Blend:
Photoshop blends the two pixel values while leaving the very darkest and lightest unchanged. Tends to take away detail defenition in an image, but can produce some subtle effects.
Soft Light & Hard Light Blends:
In both of these effects Photoshop ignores colour value altogether, but compares the darkness, or ‘grey’ values instead, and uses them as a basis to alter colour. Hard Light uses a multiply method, producing a more pronounced effect.
Vivid Light, Linear Light & Pin Light Blends:
Again, these blends use the grey value to calculate their effects. Vivid Light and Linear Light use mathematic algorithms to produce blend values, whereas Pin Light produces a more direct light and dark separation.
Hard Mix Blend:
The name says it all; pixel values are added together and then Photoshop discards locks any with a total above 255 or below 0. Unlike many of the other blends, this one is quite predictable: it tends to be completely useless…
Difference Blend:
Blends using the difference in values between the compared pixels. This tends to darken the image and produce bizarre reversed colours.
Exclusion Blend:
Very similar to the Difference blend, but has a more subtle effect with less intense colours and contrast.
Subtract & Divide Blends:
In this mode a pixel value is either subtracted from or divided by the value of the pixel beneath. Divide tends to produce a wider range of colour and contrast than Subtract.
Hue & Saturation Blends:
With the Hue selected, Photoshop takes the colour value of the top pixel and the luminance of the pixel beneath to produce its blended value. With Saturation, the colour of the lower pixel is added to the mix too.
Color & Luminosity Blends:
Similar to Hue & Saturation, but Color leaves the upper layer’s brightness unchanged, while Luminosity affects only the upper layer’s brightness.
Blending modes can be faded, made semi-transparent, added to specific layers or layer groups only, and be applied through complex masks to create some fabulous image mix effects. If you are unfamiliar with blends, I highly recommend spending some time investigating them. There’s some useful information on Photoshop’s official website, which is well worth a visit. However, unless you know these modes like the back of your hand, I found that the best way to use them is to cycle through the blends and see what happens to your image – hardly scientific, but hey, why not have some fun experimenting?