Every region in LightZone has a feathering area that is marked by an inner line that matches the contour of the region. Inside the inner line, the tool for the region has 100% effect; outside the outer line, the tool has 0% effect. In between, the tool's effect is smoothly "feathered" from 0 to 100%.
Note: This feathering is reversed if the region has been inverted.
Double-click the region whose feathering area you want to adjust.
(The control points and the inner line will become visible.)