The early printers had already organized their offices into a sort of freemasonry, under which the discipline was promoted and trade secrets protected. Each guild was composed of masters, journeymen (paid workers), and apprentices, with far more proprietors than journeymen.*
*The Duchy of Magdeburg in Germany had 27,050 independent masters and only 4,285 journeymen and apprentices in 1784; the principality of Wurzburg had 13,762 masters and 2,176 journeymen and apprentices. Thus five-sixths of the industrial establishments of the two places employed no extra help, but were one-man shops.--Industrial Evolution by Karl Bucherfrom ITU Lessons in Printing. Trade Unionism Unit VI (1958)
I would like to see a comparable breakdown of unionized workforce by cohorts. I suspect that part of the problem today is a top-heavy superstructure. I also suspect that there was little opportunity for young people in the Old Country for such reasons. It's also personally interesting to me because my family immigrated from that time and place to this country. And while preoccupied with agricultural (as was the whole nation) for almost a century, many family members eventually found their way back to the organized labor force.