I have a rigged and weight-painted letter A. I'm content with all the weights except for the letter's left shoulder (Shoulder.L) bone. See image. The deformation is crooked, not smooth. I tried the Smooth, Levels, Normalize, Weight gradient, Blur etc. tools and I can't get it right. I tried reapplying automatic weights also with no success. Is the problem with weight painting or is it the underlying geometry (however the geometry here is very simple).
How to properly smooth this "left shoulder"?
Note that the other deformations on this letter are smooth, when I rotate the bones.
(I'm using Blender 2.79b)
I'm attaching a stripped down .blend file.