In its primitive form (superposition of three horizontal
ochre, green and blue bands), this spatial procedure goes back to the
paleo-Christian time and was kept, in Rome, until the middle of the XIIIth
One of its avatars, the back-screen where blue makes a kind of a
window within the green, is very popular in Northern Italy during the Middle
Ages as a whole.
In the XVth century, it was adopted both by painters of the international
gothic movement and by all he following generations.