Britain’s first museum devoted entirely to illustration has opened in London, named for Quentin Blake — the pen behind Roald Dahl’s Matilda and the BFG — and set inside the New River Head, a restored Victorian waterworks near Islington. Beyond a permanent home for Blake’s own work, it’s built as a working centre for the whole art form, with changing exhibitions and studios rather than a single-artist shrine. For anyone who grew up inside those scratchy, generous ink lines, it’s a specific reason to cross London.