Nib asked, and Nib — askNib's tutor — drew the answer live at a whiteboard. This is the spoken transcript; enable JavaScript to watch it drawn.
How did the printing press take over Europe in fifty years? (for a curious adult who has not studied history). Cover, in this order: How were books made before the printing press?; What exactly did Gutenberg invent?; Wasn't printing invented earlier in China and Korea?; Why did printing jump from city to city instead of spreading like a ripple?; Why did books become so much cheaper?; What changed once many people could read the same words? — page 2: Gutenberg's Real Invention
Gutenberg was a goldsmith in Mainz, around the 1440s. His problem was simple: copying by hand takes months. How do you make pages fast?
Each letter is cast as a separate metal piece. Arrange them in a row to form a page, press ink on, then take the letters apart and reuse them.
Second part: a press. A screw squeezes paper against the inked type with firm, even pressure, adapted from presses used for wine and olives.
Third part: ink. Watery scribe ink runs off metal. A thick, oil-based ink clings to the raised letters and prints sharp, dark pages.
Set type, ink it, press the paper, lift the page, and repeat. Each pass makes another identical copy, quickly. That loop was the printing press's real invention.
Gutenberg's genius was assembling known pieces into one fast system, and that system is what made books ready to multiply.