Points and Picas
Points are very small units to measure both type size and the size of the space between lines of type. Typography’s point measurement system was derived from handsetting type back in the fifteenth century.
Picas are larger units used to measure lines of type.
The measurements for Points and Picas are as follows:
12 Points = 1 Pica
6 Picas = 1 inch
The most common ranges of type sizes that are used today are between 8 points and 72 points. They are the sizes that will be the default size in most word processing programs. These sizes derived from the handsetting days when type was made out of metal. The sizes back then ranged from 5 to 72 points. It was from 5 to 72 because anything less than 5 was too small to make out of metal and 72 was too heavy to carry. But these type sizes that are used today are divided into two categories. They are:
Type that is 14 point and below. Text type is used in body text or the main section of a magazine or paper.
Type that is 14 points and above. Display type is used for headers, whether it is in a newspaper, magazine, or Web site.
Although 5 to 72 points is a standard or default setting, today’s digital technology has no limits on the size of type that can be used.
When designing with type you also have to be aware of the spacing in-between the lines of text and also the length, or width, of a line of text. This must go hand-in-hand with the size of type you select. Certain type sizes look better to the eye when reading if the proper amount of spacing is present. Let’s look at some of the techniques that are used for spacing.
Line spacing is the distance between two lines of type measured vertically from the baseline to baseline. Line spacing is measured in points.
Leading is a term still used today when talking about line spacing. Leading was a term used to distinguish the line spacing in the metal type era.
Line length is the horizontal length of a line of type. The length of a line is measured in picas.
Kerning or letterspacing is the spacing in-between certain letters. Today’s word processors automatically correct the kerning problem, but sometimes a minimal adjustment is required for sufficient reading.
Tracking or wordspacing is the spacing in-between certain words. Most word processors automatically correct the tracking problem, but in some cases a slight adjustment on the tracking may be needed.
Em-Quads are used for paragraph indents. An em-quad is a square of a specific type size. If the type size is 12 point then the em-quad would be 12 points by 12 points.
Ems and ens
The em space is based on the em quad, which is the square of the type size. For example, the em quad of 48pt. Futura is 48 pts. high by 48 pts. wide. The em space measures 48 points.