Within the cells of San’Marco, Fra Angelico had demonstrated that painterly skill and the artist's personal interpretation were sufficient to create memorable works of art, without the expensive trappings of blue and gold. In the use of the unadorned fresco technique, the clear bright pastel colours, the careful arrangement of a few significant figures and the skillful use of expression, motion and gesture, Michelangelo showed himself to be the artistic descendant of Fra Angelico. Frederick Hartt describes Fra Angelico as "prophetic of the mysticism" of painters such as Rembrandt, El Greco and Zurbarán.