Revision Date: 15 January 2023

Layer Blend Modes

A layer's blend mode specifies how it is combined or 'blended' with the layers immediately below it in the layer stack.  Changing the Blend Mode on a single layer can radically alter the composite image.

To change a layer's Blend Mode, open the Properties Dialog for the layer by highlighting the layer in the Layers Window and pressing the function key F4. Double-clicking the layer in the Layers Window is an alternative method of opening the same dialog.

In the dialog the Blend Mode drop-down list offers 14 blend modes.  Click one to apply the blend mode to the layer. The new blend mode will be applied to the entire layer. It is not possible to apply a layer blend mode to part of a layer.

The order of the layers in the layers stack is important when using layer blend modes. Layer A blended over Layer B is not the same as Layer B blended over Layer A - even if the same blend mode is used.

Not all blend modes are easy to understand in classic or intuitive terms, and because of this experimentation is recommended. The Paint.NET forum is a great place for asking questions, getting tips and discovering how to use the less intuitive features of Paint.NET.

Tool Blend Modes  

The Paint Bucket, Paintbrush, Pencil, Clone Stamp, Text, Shapes, Gradient and Line/Curve tools all have options to utilize a blend mode as they are used.  When the tool is active, the list of blend modes can be found in the Tool Bar, along with the additional mode of Overwrite.

Select the blend from the list and use the tool as normal to have the blend mode applied as the tool covers the canvas. The tool and blend mode will be applied to the active layer as if the tool was being used on a new layer immediately above the active layer and the results merged down following the editing operation.

For the following discussion, these two images will be used to demonstrate the layer blend modes:

Where the term composition is used, this refers to the sum of all the visible lower layers in the image.  The final composition is how the image appears on screen or what results when the entire image is flattened.

Blend Modes

Normal

This is the default and standard blend mode. Each pixel in the layer is blended with the composition depending on its alpha value.

Multiply

Each pixel's RGB component intensity is multiplied with the pixel value from the composition. The result of this blend mode is always darker than the original.  White pixels in the blend layer are effectively rendered transparent by the Multiply blend.

Additive

Each pixel's RGB component intensity is added to the intensity of the pixel values from the composition.  The Additive blend has the effect of brightening pixels in the final composition. Black pixels in the blend layer are rendered as transparent by the Additive blend.

Color Burn

This blend mode has the effect of making dark pixels darker while lighter pixels must be blended with other light colored pixels in order to remain bright.

Color Dodge

This can be thought of as the opposite of Color Burn. Lighter pixels retain their brightness while darker pixels must be blended with other dark pixels in order to remain dark.

Reflect

This blend mode can be used for adding shiny objects or areas of light. Black pixels in the blend layer are ignored as if they were transparent.

Glow

This is the reverse of the Reflect mode: it works the same as swapping the layer positions and using Reflect.

Glow effectively brightens the composition by the amount of brightness in the blend layer.  Black pixels in the blend layer are rendered as if they were transparent.

Overlay

This is a combination of Screen and Multiply modes which uses the blend pixel intensity to determine the result.  For darker colors, this acts like Multiply. For lighter colors, this acts like Screen.

Difference

The counterpart to Additive blending. The layer pixel's intensity is subtracted from the composition pixel's intensity resulting in darker colors.  Subtraction could produce a negative intensity which is unable to be displayed, so an absolute value is returned.  Thus, both "white minus black" and "black minus white" will both produce white. Difference blend is often useful when using the Clouds effect.

Negation

At first glance this seems similar to Difference, however it actually produces the opposite effect.  Instead of making colors darker, it will make them brighter.

Lighten

The lightest pixel of either the blend layer or the composition is used.

Darken

The darkest pixel of either the blend layer or the composition is used.

Screen

This can be thought of as the opposite of the Multiply blend mode. It is used to make pixels brighter, with black being effectively transparent.

Xor

This is short for "exclusive OR", which is an advanced blending mode that is primarily used for image analysis.  Pixels in the blend layer which exactly match the composition will be rendered black. Where differences exist, colors are shown.

Overwrite

This type of blending applies what is known as "COPY" blending. In this mode, any new pixel being drawn completely replaces any pixel that was already at that location in the active layer. The differences can be seen below where a thick line has been drawn twice, each time with an Alpha value of 128 (approximately 50% transparent).

The line on the left was drawn with Normal blending. Both the car and the line are visible where the line was drawn.

The line on the right was drawn using Overwrite blending. The half-transparent pixels completely replace the existing pixels, meaning the car is no longer visible where the line has been drawn. The checkerboard pattern is visible and indicates that this portion of the image is transparent.

The Overwrite blending option can be especially useful with the Pencil Tool when editing images at the pixel level.