RotoPaint - Nuke 101: Professional Compositing and Visual Effects - page 254

The default Feather Falloff value of 1 is a linear gradient. Values above 1 are a
harder falloff, and values below 1 are a softer falloff.
11. Reset the Feather Falloff property to 1 and the Feather property to 0.
Youcanalsocreatespecificfeatheredareasinsteadoffeatheringthewholeshape.
I sometimes call these soft edges .
12. Pull out a soft edge from the Bézier itself by holding Ctrl/Cmd and pulling on a
point or several points ( FIGURE 6.15 ) .
Figure 6.15. Pull out a soft edge by holding Ctrl/Cmd.