Non-Designer’s Type Book, The, Second Edition

Kerning Metal Type

Until the 1970s, type was set in metal. Some machines set entire lines of type on metal slugs, but many machines followed the older style of using individual pieces. Regardless of the particular method, every character had its own separate metal space. If each letter is on its own piece of lead, then the letters can only get so close to each other—it’s simply not physically possible to move them closer without taking a knife and shearing off some of the lead, thereby making that character useless for further typesetting. In lines of metal type, you couldn’t even do that much. In those days, designers had to cut apart the proof sheets of type and move the printed letters around to adjust their spacing, then glue them down. ...