Print measures are units of measurement used to measure the size of printed material. ENS stands for 'Ens', which is a unit of length in typography equal to half an inch. EMS stands for 'Em Square', which is a unit of area in typography equal to the area of a square with sides equal to the height of the font size. PICAS stands for 'Picas', which is a unit of length in typography equal to 12 points.