Blending In Photoshop
Photoshop Blend modes are used, in conjunction with opacity, to control how pixels on one layer will interact with pixels on the layers below, and how Photoshop’s painting tools interact with colours already on a layer.
How do blends work?
Blend modes are used, in conjunction with opacity, to control how pixels on one layer will interact with pixels on the layers below, and how Photoshop’s painting tools interact with colours already on a layer. They control these interactions by comparing existing colour to the new colour and calculating the interaction according to the formula for the selected blend mode. When discussing blend modes, we use three terms:
- The base colour is the colour of the pixels on the lower layer (when working with the layer blend modes) or on the active layer (when working with painting tools).
- Blend colour is the colour on the upper layer (layer blend modes) or the colour is applied (painting tools).
- The result colour is the colour you see when the blend colour is added to the base colour.
Note: when working with blend modes, each pixel is calculated individually.
Assuming an opacity of 100%, here’s how each of the most 10 common blend modes calculates the relationship between the base colour and the blend colour to produce the result colour.
Normal: The blend colour replaces (hides) the base colour.
Dissolve: Used only with semi-transparent pixels, such as those along antialiased or feathered edges. Random pixels of the base and blend colours are interspersed.
Multiply: In each channel, the base colour’s value is multiplied by the blend colour’s value, producing a result colour that’s always darker (except when one of the values is white, which leaves the base colour unchanged).
Screen: Mathematically the opposite of multiply, the inverse of the base and blend values in each channel are multiplied.
Overlay: A combination of multiply and screen, dark blend colours darken the base colour and light blend colours lighten the base colours.
Soft Light: Consider Soft light to be a subtler version of Overlay, with less darkening and lightening of the base colours
Hard Light: Think of Hard Light as Overlay with a sledgehammer – dark blend colours make the base colour really dark and light blend colours make the base colour really light.
Difference: The brightness values of the base and blend colours are compared and the lesser value is subtracted from the greater value. Because black has no brightness value, no change is made. White as the base or blend colour produces grey. Where the base and blend colours are identical, you’ll see black. Tip: When trying to align the overlapping area of two photos in a panorama or two halves of a scan, set the upper layer’s blend mode to Difference. When the overlapping area is perfectly aligned, it will turn black. You can then restore the upper layer’s blend mode to normal.
Colour: The base colour’s brightness is retained while the hue and saturation of the blend colour are applied.
Luminosity: The hue and saturation of the base colour are retained while the brightness of the blend colour is applied.
Blend mode shortcuts:
Below are the blend mode short cuts you can use in Photoshop. Just press option-shift (PC: Alt-Shift) plus one of the following letters to jump to that specific mode. Note: Shift -+ and Shift -- will cycle through the blend modes.
|Z||Pin Light||B||Colour Burn|
|L||Hard Mix||A||Linear Burn|
Remember that when a painting tool is active, you’re swapping the tool’s blend mode; when a non-painting tool is active, you’re changing the layer blend mode.