Point System of the Mergenthaler Linotype Co.

This point system—adopted for convenience in measuring—is nearly identical with that of Didot, as adopted by the United States Typefounders’ Association. The size of a pica em, as understood before the adoption of the point system, was one-sixth of an inch, or .166⅔. The pica em adopted by the United States Typefounders’ Association measures .166, while the Linotype pica em measures .168. The United States Typefounders’ Association’s unit of measurement, or point, is .01383. The Mergenthaler Linotype Company’s is .014. Therefore 12 points × .014 = .168, or the Linotype pica em.

All the Linotype matrix measurements are made on the basis of .014 to a point, and .168 to an em pica. The following table will furnish an illustration of these dimensions:

Font.No. Points. Point. Em Space.
Ruby5 ×.014=.070
Agate5½×.014=.077
Nonpareil6 ×.014=.084
Minion7 ×.014=.098
Brevier8 ×.014=.112
Bourgeois9 ×.014=.126
Long Primer10 ×.014=.140
Small Pica11 ×.014=.154
Pica12 ×.014=.168

To measure Linotype matter, take an em space in the font to be measured, and ascertain how many times it is contained in the matter to be measured. The quotient will show the correct number of ems.

The length of molds is calculated on a basis of 166⅔ to an em pica, while the body or thickness of slug is calculated according to the above table.

The slug should be the same thickness at points 1, 2, 3 and 4 (Fig. 40). If the machine locks up properly, and the back knife is set right, the slug should measure 918 to 919 thousandths high from bottom of slug to top of letter.

Fig. 39.