n.p.: s.p., n.d. (1967)
9.4 x 14.5cm, 2pp full colour, limited edition postcard with on the front a minimal design by Andersen where the four colours of process printing are displayed as separate parallel lines hence the title and the joke. On the reverse: printed are the words: “POSTCARD/ POSTCARD IN FOUR COLOURS 1967/ SIGNED” and the whole is signed in black ink “Eric”. Fine.