Precisely folding nanographene Graphene nanostructures that would result from folding or rolling graphene monolayers or bilayers have been predicted to have a number of interesting electronic properties, but control over such folding processes has been limited. Chen et al. used a scanning tunneling microscope tip to fold and unfold graphene nanoislands etched on graphite surfaces at low temperatures (4 kelvin). The fold angle could be precisely controlled to create different twist angles in bilayer graphene and a tubelike edge in folded graphene. They also folded 5 ring–7 ring defects and explored this heterojunction with scanning tunneling spectroscopy. Science , this issue p. 1036