[Illustration: 10-POINT SPACES AND QUADS hair space five-to-em four-to-em three-to-em en-quad em-quad two-em three-em]
The metal blanks shown here are the regular spaces and quads belonging to a font of type of the size of 10-point. They enable the compositor to obtain the many different spacings required to make lines the required length, and to properly separate words and place them wherever desired in the line. While these thicknesses of spaces are the usual kinds for sizes of type up to 12-point, larger types may have other kinds of spaces, six-to-em, eight-to-em, and even smaller divisions. The thickness of the hair space does not always bear the same proportion to the em quad; in some sizes it is one sixth of the em, in others it may be one eighth or one twelfth. Very thin spaces (copper 1/2-point, brass 1-point), for exact spacing and justifying, are supplied by dealers.
A space of the thickness intermediate between the three-to-em and the en quad, known as a patent space, has been made for use in book work. Although it has great advantage as a substitute for two of the thinner spaces when these are needed in spacing a line, its use has been limited and it is not included with the usual assortment furnished by dealers.
The common spaces and quads for general work, when the type itself is used for printing, are about seven-eighths of the height of the type, so that they are well below the printing surface. A type-page composed with these spaces will have a little deep hole at the top of each space. These numerous little holes present a difficult surface for making a good wax mold when an electroplate is made for printing. Where much molding is to be done, higher spaces, quads, and other blanks are provided. These high spaces and quads reach nearly to the shoulder of the type.
[Illustration: Solid lines indicate one half of the mold. Dotted lines show the other half in position. Shaded portion represents type metal filling aperture in the mold. The molten type metal flows through the opening at A, down to the side B, where the matrix (not shown in this diagram) molds the face of the type. The tag of metal, called the jet, marked C, is cut off after casting. D is a narrow flange on the mold which forms the nick on the under surface of the type body.]