I recently went to see an M.C. Escher exhibition at Somerset House in London, the second time I'd gone to a dedicated display of his artwork, but much more extensive than the previous showing at the Dulwich Gallery in 2015. Escher is an artist who fascinates me, partly because his prints show incredible cartographical, architectural, mathematical, botanical and zoological detail, but also because his work was adopted by the hippie movement as an art of altered perception. The