Pleasures of Design

How type is measured

When type was cast in metal, the printing surface – the “face” – was mounted on a block of metal called the “body”. The type sizes – measured in points – refered to this metal body rather than the face itself. The proportion of the face on the body could vary considerably from one typeface to another.

This principle still applied. For example a 10 point type is one that measures 10 points from baseline to baseline when set solid (ie without any extra space being added between the lines). So it is possible for one 10 point type to look smaller than another but they will both take up the same depth from line to line.

Most typefaces that look big on the body have a large x-heigt and short ascenders and descenders.

more ... Type groups ...