Outline
Add an outline on all objects of the layer having the effect. This won't work well if shown on top of the background color of the scene. Be sure to use an object acting as a background or a floor.

Settings
- Thickness sets how wide the outline is.
- Color sets the outline's color.
Tip
When applied to an object, a thick outline can get clipped at the edges of the object's image. Increase the Padding property to enlarge the rendered area so the whole outline is visible.
Reference
All effects are listed in the effects reference page.