A painter should never speak because words are not the means at his command. Words cannot express visually dimension at a glance they can only establish their own relationship in time.
However, it is possible for a painter, at certain moments of his development to formulate some of the problems he is facing in the growth of his work. A painting cannot be explained. Words can only stimulate the act of looking.
A visual problem is never put a priori as a mathematical problem but is born in the process of painting and evolves in a state of unawareness of the painter.