Fibonacci Gauge
Fibonacci Gauge can be used in wood working as seen on this video, but I will look this up and built my own to see how it can be applied to painting.
Fibonacci GaugeI made this with Balsa wood, which is soft enough to be cut with a sharp Exacto knife. You will need four rivets and those can be found at Ace Hardware store.
I have to say this Fibonacci gauge is a nifty little tool. I have been walking around the house measuring all sorts of things and for the most part there seems to be a pattern in the way measurements repeat and follow this system.
Make your own