Back in the days when I was doing a lot of speechifying at conferences and writing the occasional column for one or another professional journal, I would often talk about our “Gutenberg moment”.
Somewhere around 1447, Gutenberg (and others) construct a printing press with reusable movable type. Not a singular invention de novo, it's the clever combining of existing innovations. The press borrowed from the vintners, beautiful permanent rag paper, precision metal casting with just the right degree of durability, inks that would adhere in a thin film to the type and resist bleeding into the paper, a rising commercial sector with mercantile fairs and trade routes crossing the continent.
Surely there was money to be made. All over Europe, entrepreneurs leap in, setting up print shops, intent on making their fortunes. The demand for luxury goods is high among the nobility, the upper clergy, the richest among the merchant classes. But the traditionalists frown on the notion of printed missals and religious tracts. They hear rumors of a 42 line Bible. Duplicated! Multiple copies scribed by a machine! Which borders on sacrilege! Does it not, Father? Their sons, however, building their own fortunes, find the printed works to be worthy markers of attainment, particularly when they can hire the finest illuminators to ink in the Initial Cap.
Most of the printers quickly go bust. Some clever few survive. Turns out there wasn’t enough of a market for those luxury items. The successful printers turned to indulgences, playing cards, and, of course, pornography. Demand ramps up so much that there’s a paper shortage near the end of the century. A printer in the Netherlands shifts all their books from quarto to octavo, multiplying their supply. And, oh, these smaller books fit neatly into a saddlebag. Portable.