Through the relationships of colour, light and sound, Sam Francis creates a visual world in which he can explore essential forms, rhythms and lines. The rich colour palette we are presented with in Trietto 4 is a characteristic of Francis's work which he viewed as the result of the union of imagination and nature. His expert knowledge of colour sequencing, together with his skilful colour manipulation during the printmaking process creates a sense of harmony in his prints that almost seems fantastical. Ruth E. Fine, art historian and former curator of modern prints at National Gallery of Art, Washington, D.C., says that to look at Francis's prints is like 'riding on a magic carpet. Voyaging in his world, his galaxies, his space, his time'.

Aquatint in colours, 1991, on Fabriano paper, signed and numbered in pencil, an artist's proof in Roman Numerals aside from the edition of 66, printed by Valter & Eleonora Rossi at Vigna Antoniniana Stamperia d'Arte, Rome, published by 2RC Edizioni d'Arte, Rome, 135.3 x 166.4 cm. (53¼ x 65½ in.)