After World War II a number of young Dutch painters, including Karel Appel (born 1921) founded the Nederlandse Experimentele Groep, which became one of the founders of the international Cobra movement in 1948, named after the capitals of the three countries of the participating members: Copenhagen, Brussels, Amsterdam. Cobra members reacted against surrealism and searched for a spontaneous, experimental way of painting with a minimum of theoretical dead weight. In the course of 1949 the Belgian author Hugo Claus (born 1929) came in contact with the movement.
Appel settled in Paris in 1950 after a clash over his mural Vragende kinderen (Begging children) for the Amsterdam town hall. The painting was considered so ‘barbaric, atrocious and violent’, that it was temporarily covered up. Claus left for Paris in the same year, where he stayed almost uninterruptedly till 1953.
De blijde en onvoorziene week was created by the two artists in December 1950. It is characteristic of the style pursued by Cobra: spontaneous drawings coloured by hand in primary colours. A subscription form had been sent out in advance, inviting subscription to the publication for the price of three guilders. As only three people subscribed, the venture could hardly be called a success. Although publication in itself was not an impromptu affair, the actual production was fast and spontaneous. As Claus recalled in 1968: ‘It was our policy to make such a small book in one afternoon. Even a minimum of encouragement would have induced us to make fifty per year’. Failing this, the second volume in the Hand-reeks van de COBRA-bibliotheek, Het wandelende vuur, was never published at all, despite its preliminary announcement.
De blijde en onvoorziene week. Hugo Claus en Karel Appel. Paris, December 1950.  leaves in wrapper. 27.5 x 22.5 cm. (De Hand-reeks, 1). Printing: Illustrations by Karel Appel, coloured by himself. Ed. of 200 numbered copies. This is no. 114 , signed by Hugo Claus and Karel Appel. 43 F 25