Blend modes

A blend mode decides how a layer’s colours combine with whatever is already on the canvas under it. Use one to lay a glow over a shot, darken with a texture, or mix two pictures.

Where: Clip tab ▸ Picture ▸ Transform ▸ Blend
Agent tools: set_video

Put the layer you want to blend on a track in front of something to blend with.
Select it and open the Picture tab.
In Transform, choose a mode from the Blend popup.

Every clip starts on Normal. The change is one undo step, and with several clips selected it applies to all of them.

Hover over the popup for a reminder of what a blend needs behind it.

The eight modes

These are in the popup’s order. “Underneath” means every layer behind this one, and the canvas background.

Mode	What it does
Normal	Draws over what’s underneath.
Multiply	Darkens, by multiplying with what’s underneath.
Screen	Lightens, the inverse of Multiply. A screened white blob reads as a glow.
Add	Adds the colours together.
Overlay	Multiplies where what’s underneath is dark, and screens where it’s light.
Darken	Keeps the darker of the two colours.
Lighten	Keeps the lighter of the two colours.
Difference	Gives the absolute difference of the two colours.

Nothing behind

A blend needs something under the layer, and over the empty black canvas it can’t do much:

Mode	Over the empty black canvas
Multiply, Darken, Overlay	The layer reads black.
Screen, Add, Lighten, Difference	The layer looks unchanged.

The Transform section warns you when that’s what’s happening, for example “Nothing behind this clip — multiply reads black here.” or “Nothing behind this clip — add changes nothing here.” Hold the pointer over the Blend popup for the same explanation.

The note looks at the clip’s whole span, not only the frame at the playhead, so it stays away if anything sits behind any part of the clip. Hidden tracks don’t count, and neither do clips with their picture turned off. With several clips selected, it’s about the first one.

It appears only while the canvas background is opaque black. Over a transparent canvas, a blend draws the layer untouched.

To give the layer something to blend against:

Use Clip ▸ Add Background to put a plate on a new track at the back. See Backgrounds.
Set a non-black Background on the Document tab. See Canvas background and timecode.

During a transition

A layer always draws as Normal for as long as it’s in a transition, whatever blend mode it has. The popup keeps showing the clip’s own mode during the overlap. Only the frames in the overlap draw as Normal.

Animate a blend mode

An action can change the mode. It doesn’t ramp from one to the other: it holds, then switches at the action’s end, and the row shows at end while you’re editing that action.

Good to know

Nest clips. The popup is greyed on a nest clip, with the note “A nest has no pixels of its own to blend — un-nest it (⇧⌘G) to blend the clips inside.” Use Clip ▸ Un-nest, blend the clip you wanted, and nest again.
Clips inside a nest. You can blend a clip inside a nest. It blends against the canvas below the whole nest, not against the nest’s own clips under it.
Adjustment clips. An adjustment clip takes no blend mode.
Matte tracks. A clip on a matte track keeps its blend mode, but it has no effect while the track is a matte.
Encoded or linear light. A project can blend in either. See Blending: encoded or linear light.

With an agent

set_video sets the mode with blend, one of normal, multiply, screen, add, overlay, darken, lighten or difference. Any mode but normal on a nest clip gets the error “clip 7 shows a nest and cannot take a blend mode”. See Tools: picture and grade.