Remove a video background (white, black or green)

Put the overlay video (for example a "subscribe" animation on a white background) on V2 above your main video, then right-click it ▸ Remove Background (or click Remove Background in Effect Controls).

Reelsmith detects the background colour from the frame edges and sets up Ultra Key for you:

• Mode: Brightness for white, black or grey backgrounds; Colour for green or blue screens.
• Keep inside (edges only): removes only the background that touches the frame edges, so white text or icons inside the animation stay visible.
• Tolerance / Softness: raise Tolerance if a light fringe remains; lower it if parts of the animation disappear.

Then scale and move the clip (Effect Controls ▸ Motion or drag it in the Program monitor) to place it, e.g. at the bottom of the frame.

Shortcuts show the Mac keys: on Windows and Linux use Ctrl for ⌘ and Alt for ⌥.