Understanding blend modes

You can think of blend modes as different rules for putting pixels together to create a resulting color. As applied in filter effects—including shadows, glow, bevel, and emboss as well as Pattern Maps—the blend mode is one of many settings that determine a color change superimposed on the original object’s pixels. Because the change is part of a filter effect, it doesn’t actually alter the original pixel values. Note that blend modes work in relation to the colors of the object itself, and don’t interact with background or underlying object colors. Changing the blend mode produces more dramatic results with some effects than with others (for example, with shadows they have negligible impact because the shadow is basically a blend with the background).

Here’s a summary of available blend modes. In the following descriptions, “top color” refers to the color superimposed by the effect, while “bottom color” refers to the color prior to applying the effect.

  • Normal
    The default blend mode. Blending of top color and bottom color pixels occurs only by varying the opacity setting. If the top color’s opacity setting is 100%, no blending occurs and only the top color is visible.

  • Dissolve
    Similar to Normal, but randomly selected top color pixels are replaced with the bottom color to create a speckled effect. The number of replaced pixels depends on the top color’s opacity (lower opacity, more replacements).

  • Multiply
    The result is a combination of the top and bottom color at each pixel position, always producing a darker value. Multiplying any color with black yields black. Multiplying any color with white leaves the color unchanged.

  • Screen
    Like Multiply, but the result is a combination of the inverse of the top and bottom color at each pixel position, always producing a lighter value. Screening any color with white yields white. Screening any color with black leaves the color unchanged.

  • Overlay
    Applies either Multiply or Screen, depending on the bottom color at each pixel position. If the bottom is less than 50% gray, it multiplies; if greater, it screens. This tends to preserve highlights and shadows from the bottom along with main colors and patterns from the top. Compare to Hard Light.

  • Soft Light
    Applies either Burn or Dodge, depending on the top color at each pixel position. If the top is less than 50% gray, it burns; if greater, it dodges. This tends to add soft highlights and shadows to the image.

  • Hard Light
    Applies either Multiply or Screen, depending on the top color at each pixel position. If the top is less than 50% gray, it multiplies; if greater, it screens. This tends to add soft highlights and shadows to the image. Compare to Overlay.

  • Dodge
    Lightens the image using lightness values of the top color at each pixel position. Dodging with black has no effect.

  • Burn
    Darkens the image using the lightness values of the top color at each pixel position. Burning with white has no effect.

  • Lighten
    The result is either the top or bottom color at each pixel position, depending which is lighter. Darker colors are replaced.

  • Darken
    The result is either the top or bottom color at each pixel position, depending which is darker. Lighter colors are replaced.

  • Difference
    The result is the difference between the top and bottom color at each pixel position, with the same result no matter which color is on top.

  • Exclusion
    Similar to Difference, but a softer effect, with the same result no matter which color is on top.

  • Hue
    The result is a combination of the hue of the top color with the lightness and saturation of the bottom color.

  • Saturation
    The result is a combination of the saturation of the top color with the hue and lightness of the bottom color. No change over grayscale (0% saturation) regions.

  • Color
    The result is a combination of the hue and saturation of the top color with the lightness of the bottom color. Because lightness values (grayscale levels) are preserved, this mode is useful for tinting grayscale images. Compare Lightness.

  • Lightness
    The inverse of the Color blend mode. The result is a combination of the lightness (luminance) of the top color with the hue and saturation of the bottom color.

Understanding blend modes