New Haven and London: Yale University Press, 1963. First Edition. Thick folio. 2000 copies printed. Consists of 80 folders with tissue-guarded original silkscreen prints and die-cuts exploring the nature of color; over 200 illustrations in total. The folders are housed with a commentary volume and clothbound book in a large drop back clamshell box and slipcase. "Interaction of Color" was the result of 30 years of experimentation culminating in a sequence of exercises fleshed out in this publication, and at Yale where Albers taught from 1950-1958. Light inevitable offsetting from tissue guards, else fine in a fine slipcase. An exemplary copy. Despite a robust edition, complete copies in nice condition are rare in commerce, as the portfolio is usually broken up for the prints.