Blend Modes Explained Simply
Simply put Blend modes in photo editing control how a top layer interacts with the layer beneath it. By changing mathematical formulas for pixel values, in addition to being able to edit image properties using brightness, contrast, hue, and saturation, you can also obtain additional visual effects by applying a variety of Blend Modes that let you darken, lighten, or add contrast without complex masking. You can download a copy of the following image here.
Functional Groups and Mode Definitions
The standard blend modes are organized into six groups based on their effect on the image.
The image above provides a representation of Group/Blend Mode/ Effect(image)/Effect (detail) and the remainder of the post covers the effects in additional detail.
1. Normal Group
No special blending math occurs; these modes are primarily affected by opacity.
- Normal: The default state where no special blending occurs.
- Dissolve: Does not apply transparency effects to pixels. Instead, it blends by dithering pixels on or off, creating a “snow” or particle effect.
2. Darken Group (Hides White)
The result is always a darker image. White on the blend layer becomes invisible.
- Darken: Replaces lighter colors on the base with darker areas from the blend layer.
- Multiply: Similar to overlapping transparencies; each color is darkened, and white is ignored.
- Color Burn: Darkens the base and blend colors while increasing contrast and saturation.
- Linear Burn: Decreases the brightness of the base color.
- Darker Color: Displays the darkest pixels between the base and blend layers without altering colors.
3. Lighten Group (Hides Black)
The result is always a lighter image. Black on the blend layer becomes invisible.
- Lighten: Displays the lightest pixels between the base and blend layers.
- Screen: The opposite of Multiply; similar to taking multiple exposures on a single film frame. Black is ignored.
- Color Dodge: The opposite of Color Burn; reduces contrast based on the base color.
- Linear Dodge (Add): The opposite of Linear Burn; increases brightness.
- Lighter Color: Displays the lighter pixels between the base and blend layers without altering colors.
4. Contrast Group (Hides 50% Gray)
These modes increase contrast by applying darkening modes to dark areas and lightening modes to light areas. 50% gray is invisible.
- Overlay: Multiplies dark colors and screens light colors. (Overlay = Screen + Multiply).
- Soft Light: Similar to Overlay but uses Darken/Lighten for a subtler, diffused light effect.
- Hard Light: Acts like a harsh spotlight; multiplies if the blend is darker than 50% gray and screens if lighter. (Hard Light = Linear Burn + Linear Dodge).
- Vivid Light: Uses Color Dodge and Color Burn; higher contrast than Hard Light.
- Linear Light: The blend color acts as a light source, dodging (brightening) or burning (darkening) the result.
- Pin Light: Replaces colors based on whether they are lighter or darker than 50% gray. (Pin Light = Lighten + Darken).
- Hard Mix: Reduces the image to eight primary colors (Red, Green, Blue, Cyan, Yellow, Magenta, White, and Black), creating a posterized effect.
5. Comparative Group (Inversion & Cancelation)
These modes focus on the differences between images.
- Difference: Subtracts the lightest color from the darker color. White inverts the base, while black produces no change.
- Exclusion: Similar to Difference but with lower saturation and luminance.
- Subtract: Subtracts the blend color from the base, darkening the image.
- Divide: Divides the blend color from the base, lightening the image.
6. Component Group (Color Attributes)
These modes work on specific qualities of color.
- Hue: Preserves the luminance and saturation of the base while using the hue of the blend.
- Saturation: Preserves the luminance and hue of the base while using the saturation of the blend.
- Color: Preserves the luminance (detail) of the base while using the color of the blend.
- Luminosity: Preserves the hue and saturation of the base while using the detail (luminance) of the blend.
7. Specialized Tool-Based Blend Modes
Two specific modes are available only for brushes and shape tools, accessible via the Control Bar rather than the Layers palette.
- Behind: Paints only on the transparent portions of a layer, protecting existing pixels.
- Clear: Acts as a “pixel-eating machine,” turning shape tools or brushes into erasers. This is particularly effective for creating complex cutouts in shapes without using selection tools.