Thank you so much for you advice ptoing

I've followed it and made something in the same way of your exemple.


I've cheated a little bit for the outline, using the layers filters. Saved some time even if it's not "pure two colors".
As you guessed : the full brain stands for 100%, the empty brain for 0%. Then you have the others 90%, 80%, etc...
I'll try to do some numbers if I have some time. School makes me forget that cool forum.
