The Printing Press

How a Book Was Made

Before 1450, books in Europe were copied by hand, one at a time. A scribe’s mistake was copied again by the next.

Woodblock printing was long established in China: the Diamond Sutra in the British Library, printed in 868, is the oldest dated printed book to survive. A woodblock carries a whole page cut in one piece of wood, and one wrong character means patching or recutting the block. In the Qingli years (1041–1048), Bi Sheng made single characters of clay, fired them hard and set them in a frame to print, as Shen Kuo recorded. In Korea, books were printed from metal type: the Jikji, printed at Heungdeok Temple in Cheongju in 1377, is the oldest surviving book printed with movable metal type.

Left: a woodblock, a whole page in one piece of wood · right: movable type, one piece per letter

Gutenberg’s Method

A letter is cut, reversed, on the end of a steel bar: the punch. Struck into a softer block of copper, it leaves a sunken letter: the matrix. The matrix goes in the bottom of the hand mould, the two halves close, molten metal is poured in, and it sets in seconds.

The two halves of the hand mould slide sideways: narrow for an i, wide for an m. The body and the height stay the same, so every letter stands the same height and they set into a level page. The metal is mostly lead, with tin and antimony; it melts low and sets fast, and the antimony expands a little as it sets, so the letters come out sharp. The ink is oil-based, linseed oil boiled to a varnish and mixed with lampblack, so it holds on metal.

Punch (steel) → matrix (copper) → hand mould · the tools on the bench are 2.5 times life size

Set Backwards

The compositor holds a composing stick in the left hand and takes letters one by one from the case with the right, setting them in a line. Seen from the faces, the line is backwards: it runs right to left, and each letter is reversed.

In printing, the paper lies face down on the type and is turned over to be read, which swaps left and right once more. Set backwards on the type, it reads the right way on the page.

Top: the faces in the composing stick · bottom: how it prints

Locking Up and Inking

The set lines are moved, line by line, onto a flat stone to make a page. Wooden strips go round it, wooden wedges squeeze it tight, and the whole page is locked in an iron frame, so it can be moved without falling apart. The locked page is the forme.

Ink goes on with two leather ink balls, stuffed with wool or horsehair, on wooden handles. The pressman first spreads the ink on the ink block, then beats the faces of the type with the balls, so each letter takes a thin coat.

Iron chase · wooden strips and wedges · two leather ink balls

One Pull

A dampened sheet goes on the tympan, placed on its points; the frisket, a frame with windows cut in it, folds down to mask what should not print; then the tympan folds down onto the forme. A turn of the rounce runs the carriage along its rails under the platen.

The pressman pulls the bar, the screw turns, and the brass platen presses down on the sheet. The platen moves only a short way, and the thread turns the pull of an arm into a great pressure. The bar goes back, the carriage runs out, the tympan opens and the printed sheet comes off.

Ink → sheet → frisket → tympan → run in → pull → run out → take off

Taken Apart

The frame is oak: two cheeks, a cap on top, feet below. The head between the cheeks holds a brass nut, and the iron screw turns in it. The foot of the screw sits in a square hose, and the platen hangs from the hose. The rails run out of the frame, and the carriage and tympan travel on them.

Taken apart, whichever piece the pointer rests on is lifted out and named.

Cut Open: Casting a Letter

Cut open, the hand mould has a narrow upright slot in its middle, the copper matrix at the bottom and a mouth at the top. Poured metal fills the slot first and leaves a stub in the mouth.

Once it has set, the halves part, the letter comes out and the stub, the jet, is broken off. Dressed, it is a piece of type. Change the matrix and the same mould casts the next letter.

Cut open: the two halves · slot · copper matrix · mouth · 2.5 times life size

Forty-Two Lines

Gutenberg’s best-known book is a Latin Bible, finished before 1455. Each page has two columns, most of them 42 lines long, hence the name “42-line Bible”; the first pages have 40. It runs to 1,282 pages in two volumes.

According to the Gutenberg-Museum in Mainz, about 180 copies were printed, about 150 on paper and 30 on vellum. To make it look like a manuscript, 290 different characters were cast, including ligatures and abbreviations. About 20 people worked on it in the workshop. 49 copies survive today. Before it, the workshop printed Latin grammars and indulgences; one indulgence, dated 22 October 1454, is the earliest precisely dated print in Europe.

About 180 copies · 42 lines a column · 290 characters · 49 survive

What It Changed

Printing spread across Europe within a few decades. By 1500, more than two hundred towns had a printing shop. The Incunabula Short Title Catalogue (ISTC) records about 30,000 editions printed from movable type before 1501.

Every copy from the same setting has the same pages and the same words. Readers could cite a page and a line, and a mistake corrected once was correct in every later copy. One book could reach many cities at once: in 1517 Luther’s theses were reprinted in several cities within weeks. In 1543 Copernicus’s On the Revolutions was printed in Nuremberg, in about 400 to 500 copies.

Around 1450: Mainz · 1500: more than two hundred towns · about 30,000 editions