Authors:

The painting is not on a surface, but on a plane which is imagined. It moves in a mind. It is not there physically at all. It is an illusion, a piece of magic, so that what you see is not what you see.

Philip Guston, Clark Coolidge (2011). “Philip Guston: Collected Writings, Lectures, and Conversations”, p.278, Univ of California Press
The painting is not on a surface, but on a plane which is imagined. It moves in a mind. It is not there physically at all. It is an illusion, a piece of magic, so that what you see is not what you see.