" Another method which you can utilize, developed by Freemasonry (which is nothing but a kind of European imitation of the mystical dervish lodges, knowledge of which was obtained during the Crusades), is to create a Black and White Grid on your floor. Various types of black and white grid patterns and spirals are effective. The white represents our world, and the black represents the alternative universe. Bringing them together in a grid creates a union of the two worlds, transforming the space into a vehicle for the magickian. "

― Laurence Galian , Beyond Duality: The Art of Transcendence