Zeitvertreib

German brand of very high quality wooden jigsaw puzzles, understood to have been productive c1920s-1930s. The examples I have so far seen are cut as a single, intricately weaving and continuous line, before being cut through with small straight cuts to form the individual pieces.
This is a style reminiscent of the British "Expert" brand, along with the German examples from Raphael Tuck & Sons range, such as can be seen in this David Copperfield example.