So kearning is mostly a product of computer printing? I guess it was done for some Bible editions and other highly esteemed books. For these books the time was sometimes taken to do kearning.
Well, it could be done by a craftsman printer, but on a very limited basis -- and it wouldn't be true kerning as the term is understood with today's rubber-type tech.
Say you had a biblical verse that began with a drop cap "T", with the descender covering, say, five lines. Well, you could set up the job so that the body type was laid in under the T and you could space out each line to justify left and right with "em" and "en" thins to alter the width of the spaces.
My dad was a jobbing printer and I grew up setting wedding invitations etc. and printing them on a foot-operated platten. It was an astonishly demanding craft and, despite the utility of computer typesetting, we're poorer for the loss of those arcane skills, if only in for the satisfaction of doing a first-rate job by eye, hand, and wit.
What was even harder was writing newspaper headlines in hot metal, especially if you worked for a paper that liked a tight fit on the decks. Screams at edition time if the hed you wrote bounced. Today, you just condense and kern it.
When headlines were set using a machine that used a photo process, which I think started in the mid fifties, type kerning became a real possibilty, as did special effects.
Body type, when still set in lead, made do with combinations of characters called ligatures instead of kerning. Ligatures where combinations of letters like t and h, or f and l, and the like. Photo typesetting, using negative images of type stored on glass or film or trasnmitted by CRTs, made kerning possible on text.
When computers began to take over the typesetting business in the early 70s, kerning became widespread before moving to PCs (and by that I mean the Macintosh) in the 80s.