"In 1969, the publisher Robert Laffont launched the literary equivalent of Prospective 21e Siècle: the imprint Ailleurs et Demain - Elsewhere and Tomorrow, in English - dedicated to science fiction and under the direction of Gérard Klein. Over the coming years Ailleurs et Demain would publish translations of works by giants of the genre such as Philip K. Dick, John Brunner, Frank Herbert, and Arthur C. Clarke along with novels by French s.f. writers like Jacques Sternberg, Michel Jeury, and Klein himself . Klein was an admirer of the Prospective series and decided to package A & D fiction using the same process, called Héliophore and originally developed in the 1930s by Louis Defay to transform aluminum paper for printing. Some of the Ailleurs Et Demain designs closely resemble specific Prospective 21e Siecle sleeves, while others are new but clearly inspired by the series. (With both the albums and the novels, nobody seems to know the identity of the designers, who were in-house and uncredited). The design style, which eventually extended beyond silver to gold and copper book covers, was maintained for over 20 years, before being abandoned"
-- from my essay "This Was Tomorrow", published 2014