measured in ems of the size of type used. An em is a square of the body , and varies in size with each size of type. Thus, an 8-point em is 8 points deep and 8 points wide; a 12-point em is 12 points deep and 12 points wide. The common method of measuring the quantity of type on a page is by using the em as the unit, the number of ems in the line being multiplied by the number of lines on the page. The term em is applied in many ways to type; the em dash is one cast on a square body, the em fraction is a fraction cast on a square body, and so with type borders and other characters.

Before the adoption of the point system type sizes were designated by a variety of names which were meaningless so far as indicating their sizes was concerned. In the point system the size of 12-point corresponds to the old pica. Pica has been a standard type in many countries for a long time, though it has not always been uniform in size. All type founders made pica types, but all picas were not the same size in this country until after the adoption of the point system in 1887. The old names pica and nonpareil (half pica, or 6-point) still survive as convenient terms to use in naming these sizes.

For convenience and economy in the composing room the leads, slugs, rules, metal and wooden furniture, wood type, and other composing material are used in lengths graduated by 12-point or pica. When leads or rules are spoken of as being twenty picas, or twenty ems, it is understood that they are twenty 12-points long. Pica gages are scales marked off in units of 12-point (and half, or 6-point). A graduated composing stick is made to set to measures of 12-point and half.

It will be remembered that the point size was given as approximately 1⁄72 of an inch. Actually a point is .013837 of an inch, but for convenience the simpler fraction of 1⁄72 is sufficiently accurate for composing-room purposes. This makes the 12-point or pica 1⁄6 of an inch. Shop custom measures the items of a page in points, and the page itself or its chief divisions by picas. Paper, sizes and other large dimensions are measured in inches.

It is important for the apprentice to learn these units of measurements and their relation to each other in order to make quick calculations for line lengths, page sizes, margins, etc.

Spaces and Quads

Fig.  4

Trade custom gives the name spaces to the small type blanks and quads to the larger type blanks. These are further specified according to their thickness or fractional part of the em, or square, as 3-to-em, 4-to-em, 5-to-em (hereafter in this treatise, for convenience, termed respectively the 3-space, 4-space, 5-space). Very thin blanks are hair spaces or justifiers. The en quad (half the square) is sometimes called the thick space.2 The large blanks are the em quad 2-em quad, and (for types of 12-point and smaller) 3-em quad.

To the beginner the difference between some spaces and quads is not always clear because of the frequent identity of size in different type bodies. Thus, a 3-space of an 18-point font is 18×6 points, which is the same as a 3-em quad of 6-point. The difference between the two is in the position of the nicks (except where spaces and quads are cast without nicks). On the 6-point quad the nick is along the 3-em side, while on the 18-point space it is across the narrow 6-point edge. The identity in size is often a convenience, when quads or spaces of one size are exhausted, by allowing the use of pieces from another font.

The apprentice should become familiar with these regular spaces of his case at the outset. He may learn to distinguish them by putting one of each thickness side by side frequently for comparison. By doing this with each size of type as he comes to use it he will soon learn to distinguish the spaces at a glance, to select quickly the space he wants, and to sort them properly in distributing.

These four regular thickness of spaces meet most of the requirements of type composition. Besides their own individual widths they may be combined into any other widths for spacing and justifying lines. The following table, showing twenty-four different widths less than the em which can be made with the four original spaces, should be studied by the beginner who is in despair because he cannot find just the right thickness to fit his line.

2 Note.  The 3-space is often miscalled the thick space; but as it is commonly known as the normal space (i.e. neither thick nor thin) it seems illogical to call it also a thick space. The en quad or any space thicker than the 3-space is obviously a thick space.

A Simple Spacing Table

Taking 60 as the common denominator of the five blanks, including the em quad, which would be 60⁄60, the en quad is 30⁄60, the 3-space is 20⁄60, the 4-space is 15⁄60, and the 5-space is 12⁄60. By combining the various spaces the following fractions of the em square may be obtained: