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Graphical Art Group

Typical operations from popular paint packages.

Overlay:
  Multiplies or screens the colors, dependent on the destination color. Source color overlay the destination while preserving its highlights and shadows. The destination color is not replaced, but is mixed with the source color to reflect the lightness or darkness of the destination. Dark parts on the base layer become darker, and light parts become lighter. Math formula is same as SVG and Gimp.
Screen:
  The source and destination are complemented and then multiplied and then replace the destination. The resultant color is always at least as light as either of the two constituent colors. Screening any color with white produces white. Screening any color with black does not change the other layer. Using the Screen mode is similar to projecting multiple photographic slides simultaneously onto a single screen. A lighter picture is the result. Math formula is the same as used by SVG and Gimp. This is identical to OR.
Burn:
  Darkens the destination color to reflect the source color. Burning with white produces no change. In photography, burning is a technique used in a darkroom to increase the exposure in particular areas of the image. This brings out details in the highlights. Math formula is the same as used by SVG and Gimp.
Dodge:
  Brightens the destination color to reflect the source color. Dodging with black produces no change. The result color is a lightening of the source color to reflect the underlying layer color by decreasing the contrast. If the source color is pure black, the result color is the underlying color. In photography, dodging is a technique used in a darkroom to decrease the exposure in particular areas of the image. This brings out details in the shadows. Math formula is the same as used by SVG and Gimp.
Difference:
  Subtracts the darker of the two constituent colors from the lighter. This is the same as Subtract except that the absolute value is used. Subtract colors which would be black due to clipping become visible instead. Differencing with white inverts the destination color. Differencing with black produces no change. Math formula is the same as used by SVG and Gimp.
Hardlight:
  Multiplies or screens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened as if it were screened. If the source color is darker than 0.5, the destination is darkened, as if it were multiplied. The degree of lightening or darkening is proportional to the difference between the source color and 0.5. If it is equal to 0.5 the destination is unchanged. Using pure black or white produces black or white. The effect is similar to shining a harsh spotlight on the destination. This mode is useful for creating the appearance of shadows on a layer. You might use this mode to combine two photographs and obtain bright colors and sharp edges. Math formula is the same as used by SVG and Gimp.
Softlight:
  Darkens or lightens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened. If the source color is darker than 0.5, the destination is darkened, as if it were burned in. The degree of darkening or lightening is proportional to the difference between the source color and 0.5. If it is equal to 0.5, the destination is unchanged. Using pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white. The effect is similar to shining a diffused spotlight on the destination. A layer with pure black or white becomes markedly darker or lighter, but does not become pure black or white. Soft light is not related to “Hard light” in anything but the name, but it does tend to make the edges softer and the colors not so bright. Math formula is the same as used by Gimp; SVG formula differs.