Typography is design for reading; a set of visual choices designed to make a written message more accessible, more easily transmitted, more significant, or more attractive. Some letters are more legible, some are designed for particular technologies, and some strike us as having intrinsic emotional associations. What determines the shapes of the letters we use? ‘Perfect letters’ explains how our capital alphabet comes from the letters the Romans cut in stone, and our small letters come from the handwriting of Renaissance scribes. It also discusses the invention of printing in the 1440s, the ‘new typography’ movement of the 1920s that promoted sans serif typefaces, and more recent ideas about letter construction.