Time Traveller One... Golden Mean Grid
There have been various means devised to create interesting proportions within painting spaces. Possibly the best known device was the Golden Mean, otherwise known in the Middle Ages as the Divine Proportion. It is based upon a ratio of 1: 1.618, so if the height of the painting is 1 metre, then the width would be 1.618 metres long. For fans of Dan Brown's The Da Vinci Code, the Fibonacci Series is the closest in rational numbers to this proportion.

This irrational proportion gives rise to lines and curves which help to suggest the placement of various objects within the painting space.