We have the art of paper-cutting on the Post this week, and it is indeed very much an art and not simply a crafty pastime. Joanna Koerten (1650-1715), a multi-skilled Dutch artist, is best known as a knipkunstenaar or papercut artist whose work is stunningly delicate and complex. It is hard to believe what she achieved with a single sheet of paper and a pair of scissors. This is 'Virgin and Child with St John' (c1703, V&A).