Unlink Corners, like the Contour > Break command , breaks closed Contours or splits a closed contour into several open contours. However, instead of leaving the points right on top of each other at a break point, “Unlink Corners” breaks contours at each corner into separate overlapping sections, and adjusts each former corner vector a little (while maintaining their former shape) such that they cross. This allows FontLab to keep contours filled, and makes further element editing more comfortable than it would be after a Break operation.
To “Unlink Corners,” first select one or several corner nodes, and then choose the Unlink Corners command in the Contour menu or in the node’s context popup menu.
When editing with unlinked corners, you may find that some areas occasionally change their fill (become black or white when you want the opposite). Use the Fill tool (F key to activate, click in the area for white or Alt-click for black) to fix these areas.