Hi Brian

I have been searching the Forums a bit more and have come across the Vesicle script which is close to something I have had a problem with creating a clean S form - see attached image created in adobe illiustrator (and then imported into MOI later)

The red line is my best fit using as minimal a set of control points and anchor control arms so it makes a clean flowing double form. The dotted circular line shows my loose guide circles and centre's. Visually it has a slight flat zone between the 2 dotted circles at loosely the 60% high crossover section.
To refine this S shape further I had been wondering about using 2 opposing spiral forms and joining the ends together tangentially - will take a bit of juggling !

Any mathematically clean solutions that pop to mind ?

Best wishes

Andy