From Idea e Spazio

In 1963, the artist was commissioned by Madeleine de Harting, director of "Les Cent Bibliophiles de France et d'Amerique", to illustrate a volume of poetry by his twin sister Egle Marini.  This was the first time the artist experimented in depth with the technique of color etching.  Titled Idea e Spazio, the portfolio of 12 etchings, signed by the artist, was printed in an edition of 100 and 28 H.C. by Atelier Crommelynck.

Source: Guastalla and Toninelli, Marino Marini Engravings 1914-1970