Outset Boundary is a modeling tool that performs the reverse of Blender's native Inset operation on boundary edges. It allows users to quickly increase the margin of selected faces, functioning on both outer boundaries and inner hole edges. The tool includes built-in handling for overlapping faces and 90-degree corners, automatically merging intersections and generating quads where possible.

In addition to flat surfaces, the tool supports non-flat geometry and includes a rotation setting to angle the newly generated faces along the original edges, which is useful for creating curved hard-surface models. Additional settings include an adjustable intersection threshold distance and an option to keep boundaries selected for repeatable operations. The tool is accessed directly from the 3D viewport context menu while in Edge Edit Mode.