The machine for engraving a matrix in intaglio is operated in much the same manner as that for engraving a punch in relief. The same patterns are used, but the operator traces on the inside of the raised outline instead of on the outside. Besides following the outline, the operator guides the tracers over all the surface of the pattern within the outlines; otherwise the letter would appear in the matrix in outline only. The matrices are cut in steel and in watchmakers' nickel, and the work is so accurately done that about half the labor of finishing is saved.

It will be noted from the foregoing that all three processes of engraving end in the production of an unfinished matrix.

The adjusting of the matrix to the mould is technically called "fitting," and requires great skill. If type are cast from unfitted matrices, be the letters ever so cleverly designed and perfectly cut, when assembled in the printed page they will present a very ragged appearance. Some letters will appear slanting backward, others forward, some be above the line, others below; some will perforate the paper, while others will not print at all; the distances between the letters will everywhere be unequal, and some will print on but one edge. Indeed, a single letter may have half of these faults, but when the matrices are properly fitted, the printed page presents a smooth and even appearance.

The mould for this purpose is made of hardened steel, and in it is formed the body of the type. The printing end is formed in the matrix. The mould is provided at one end with guides and devices for holding the matrix snugly against it while the type is being cast, and for withdrawing the matrix and opening the mould when the type is discharged. At the opposite end from the matrix is an opening through which the melted metal enters. The moulds are made adjustable so that each character is cast the proper width, the opening of course being wider for a "W" than for an "i." Only one mould is necessary for one size of type, and with it all the matrices for that size may be used. Commercially, however, it is often necessary to make several moulds of the same size in order to produce the requisite amount of type.

After the adjustments are made, the casting of the type follows. Type are now cast in a machine which is automatic, after it is once adjusted to cast a given letter. The melted type metal is forced by a pump into the mould and the matrix, and when solidified, the type is ejected from the mould and moved between knives which trim all four sides. The type are delivered side by side on a specially grooved piece of wood, three feet long, called a "stick," on which they are removed from the machine for inspection. Type are cast at the rate of from ten to two hundred per minute, according to the size, the speed being limited only by the time it takes the metal to solidify. To accelerate this, a stream of cold water is forced through passages surrounding the mould, and a jet of cold air is blown against the outside.

The automatic casting machine performs six different operations. Formerly, all of them, except the casting itself, were done by hand, and each type was handled separately, except in the operation of dressing, or the final finishing, where they were handled in lines of about three feet in length.

After the type have been delivered to the inspector, they are examined under a magnifying glass and all imperfect type are thrown out. The perfect type are then delivered to "fonting" room, where they are weighed, counted, and put up in suitable packages in proper proportion of one letter with another, ready for the printer.

Formerly the various sizes of type were indicated by names which had developed with the history of type making. It was a source of considerable annoyance to printers that these old standards were not accurate, and that two types of supposedly the same size, and sold under the same name, by different makers, varied so much that they could not be used side by side. Of recent years the "point" system, by which each size bears a proportionate relation to every other size, has done much to remedy this trouble, and now nearly all type is made on that basis. An American point is practically one seventy-second of an inch. Actually it is .013837 inch. It was based on the pica size most extensively in use in this country. This pica was divided into twelve equal parts and each part called a point. All the other sizes were made to conform to multiples of this point. The point is so near a seventy-second of an inch that printers frequently calculate the length of the pages by counting the lines, the basis being twelve lines of 6 point, nine lines of 8 point, eight lines of 9 point, and six lines of 12 point to the inch. This calculation is really quite accurate.

The following table will show the old and new names for the various sizes:—