Also starring this month are an Escher paradox print and a Venice watercolour by John Singer Sargent

Our pick of the best objects up for sale in London and New York

With copyrights from 1928 expiring, thousands of creative works are now free to share, copy and build upon

Museum of Fine Arts, Houston takes a serious look at the work of the Dutch printmaker, whose mind-bending illustrations have adorn bedroom walls the world over

Exhibition of graphic artist and master of illusion takes place at Fries Museum in the Dutch city of Leeuwarden