How the press actually works

Written 19 Aug 2026, after three M-04 takes came back with men gripping press frames that do nothing, ink applied to a forme already under the platen, and a bar hauled with no carriage run in. The model will render whatever it is told and invent the rest, and what it invents is a costume-drama pantomime of printing. This page is the mechanism, so a prompt can name the beat the shot is actually on.

The 1539 Wittenberg shop used the common press — a wooden screw press whose working parts are unchanged in essentials from Gutenberg to the end of the eighteenth century. The earliest full description is Joseph Moxon, *Mechanick Exercises on the Whole Art of Printing* (1683), a century and a half late but the standard source for the hand-press period; where 1539 differs it is by being plainer, not different in kind. Pettegree, Brand Luther, describes the Wittenberg shops themselves.

The parts, by name

Frame — two heavy upright oak posts braced to the ceiling joists, with a head and a winter (the cross-members) between them. The whole press is braced against the building because the pull tries to lift it.
Screw and bar — a large wooden screw (the spindle) turning in the head. The bar is a stout iron-shod wooden lever through the box of the spindle, at chest height, on the pressman's right. He pulls it toward himself through a quarter turn or less, and it springs back; it is never wound round and round like a wheel.
Hose and platen — the platen (the flat pressing block) hangs beneath the screw in a wooden box, the hose, so that it comes down flat and does not turn with the screw. The platen is about half the size of the forme — which is why every sheet takes two pulls.
Coffin, bed and stone — the forme of type sits on a smooth stone in a wooden tray (the coffin) on the sliding carriage.
Rounce and girts — the carriage is run in under the platen and back out again by a crank (the rounce) turning a drum with leather straps (the girts). Nobody shoves the carriage by hand.
Tympan and frisket — two hinged frames at the outer end of the carriage. The sheet is laid on the parchment-covered tympan; the frisket, a cut-out paper or parchment mask, folds down over it to keep the margins clean; then both fold down together onto the forme.
Ink balls — a pair of them: sheepskin stuffed with wool over a wooden cup and handle. Ink is taken from an ink block and **the two balls are worked against each other** to spread it evenly before the forme is beaten.

The cycle, in order

Two men work a press and swap jobs through the day: the puller at the bar, the beater at the ink balls.

1. Carriage run out on the rounce, tympan and frisket standing open. 2. The beater charges the balls from the ink block, works them together, and beats the forme — two or three quick dabs across the type. 3. The puller lays a damp sheet on the tympan, drops the frisket over it, and folds both down onto the forme. 4. He winds the rounce; the carriage runs in until the first half of the forme is under the platen. 5. He pulls the bar: the screw drives the platen down, he holds it a moment, and lets the bar spring back. 6. He winds the carriage in the rest of the way and pulls a second time for the other half of the forme. 7. Carriage runs out, tympan and frisket lift, and the puller **takes off the sheet and lays it on the heap** — the growing stack of printed sheets on the paper bench at his elbow, set at about 75° to the carriage so his hand does not have to travel. He does not hang it. Moxon's list of what is "mingled and lost in the name of Pulling" ends exactly there: *"Picks the Form, Takes off the Sheet, and Lays it on the Heap"* (§24).

While the puller is at 4–6, the beater is re-charging his balls. **The two men never work the same forme at the same moment** — one operation on a press at a time, always.

A caveat that applies to everything below

Moxon is London, 1683 — a century and a half after this film, in another country. He is the earliest full description there is, and the common press did not change in essentials over that span, but nothing below is a Wittenberg source. Where a beat below carries dramatic weight, that gap is worth saying out loud rather than citing Moxon as though he were there.

The one German witness close to our date is Jost Amman's Der Buchdrucker, from Hans Sachs, Eygentliche Beschreibung aller Stände auff Erden (Frankfurt, 1568) — [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Buchdrucker-1568.png). Read against the plate itself rather than a description of it, it corroborates more than the coarse shape, and on one point it corrects us:

The heaps are there, and they are big. Two thick stacks of paper sit on a low bench in the immediate foreground, right at the press — many quires deep, not a few sheets. One carries a sheet lying open across the top; the other has a cloth or waste sheet draped over part of it, which is what Moxon has the pressman cover a wrought-off heap with. So the heap at the press is German and 1568, not just English and 1683.
Two men, two jobs, at the run-out carriage. One works the hinged tympan/frisket frames — the big frame stands open at the left with a sheet lying on it — while the other leans over the forme with **a ball in each hand**. That is the beat M-04's row names.
Nothing is hanging up to dry anywhere in the picture. Consistent with drying being a separate operation done elsewhere, though a single woodcut is weak evidence for an absence.

Treat the plate as a composite of the trade rather than one instant: the puller at the tympan and the beater at the forme are shown together, where Moxon is explicit that the two never work the same forme at the same moment.

What happens to the sheet after that (corrected 20 Aug 2026)

Hanging is not part of the press cycle, and it is not done a sheet at a time. It is a separate bulk operation, done later, by somebody else:

Sheets pile up on the paper bench all through the run. Every so often the beater looks the heap over — Moxon, on why the bench is angled toward him: so "his Companion has a nearer access to it, to look over the Heap, as he frequently does, to see the constant Complexion of the Work" (§24). Note what this does and does not say. Moxon documents a man **looking the heap over**; he nowhere describes one holding a single sheet up to a window. Reading that across to one sheet against the light is our inference — a short one, and it gives the gesture a working reason instead of a decorative one, but it is inference, not the source.
When the whole heap is wrought off, the pressman takes it off the paper bench, sets it on the floor, covers it with a waste sheet, and "gives notice to the Boy, or to the Ware-house-keeper, to fetch it away and Hang it up to Dry" (§24). In a 1539 Wittenberg shop that is the apprentice; there is no warehouse-keeper.
The hanging itself happens in the drying place, off the peel — a long T-shaped board on a handle. Sheets go up in doublings of roughly a quire or half a quire, "about seventeen Sheets, more or less," folded over the peel two doublings at a time, slid onto a rack and the peel drawn out from under them. Successive doublings lap about two inches over one another rather than hanging edge to edge (§25 ¶1, "Of Hanging Paper").

So a shot of one man hanging one sheet on a line is wrong twice over: wrong person, wrong operation. What he does with the sheet in his hands is lay it on the heap.

The paper is wet before it is printed

The dampness in a fresh sheet is mostly water, not ink. Paper is wetted the day before: dipped quire by quire through a tray of fair water — the back of the quire drawn through, quickly if the paper is weak and spongy, slowly if it is strong and stubborn — laid down in alternating wet and dry layings, then pressed overnight so the moisture spreads evenly (§24 ¶9, "Of Wetting Paper"). That is what the apprentice is carrying on his shoulder in M-04: a **wetted ream**, heavy with water.

What that means on screen: a just-printed sheet is limp. It sags between the hands, the corners droop, it does not hold itself flat, and it is faintly translucent against a window. The ink on it is minutes old and still **wet and glossy**, so it throws a specular sheen where raking light crosses it and reads blacker and shinier than the dried sheets overhead. The platen has embossed the type into the damp paper, so the sheet carries a slight relief.

Pace

Roughly 240 impressions an hour, four a minute: a full sheet through the whole cycle in about fifteen seconds. So an eight-second clip is **half a cycle**, not a whole one — write the beat the shot is on (beating the forme and running in, say, or the two pulls and taking the sheet off) rather than asking for the whole thing and getting a fast-forward.

What keeps coming back wrong

A man holding a press upright with nothing in his hands, or gripping the frame post as though it were a lever. Every hand in frame should be on the bar, the rounce, the balls, the tympan or a sheet.
Inking the forme while it is under the platen, or while the bar is being pulled. The forme is only inked when the carriage is run out.
The bar swung like a capstan or a steering wheel. Quarter turn, pulled toward the body, sprung back.
The carriage pushed by hand; the rounce and girts are what move it.
Sheets pegged to the line with clothes pegs. They hang over the cord, lapping over one another, put up in bunches off a peel.
A pressman hanging his own sheet straight off the press. He lays it on the heap; the boy hangs the whole heap later.
Both presses working in perfect unison, or a press working with nobody at it. The idle press has its balls hung up on pegs and stands dead still.

Sources: Joseph Moxon, Mechanick Exercises on the Whole Art of Printing (1683) — §§24–25 quoted above from the searchable text of the 1896 Typothetae reprint of Vol. 1, [archive.org](https://archive.org/details/mechanickexercis00moxo_0); the two-man division of labour at the moment the sheet comes off is also what the earliest German picture of a press room shows, Jost Amman's *Der Buchdrucker in Hans Sachs, Eygentliche Beschreibung aller Stände auff Erden* (Frankfurt, 1568): one man taking the printed sheet off, the other inking the type with balls — [Smithsonian digital edition](https://library.si.edu/digital-library/book/moxonsmechanicke21683moxo); [NMAH, "Wooden Hand Presses"](https://americanhistory.si.edu/collections/object-groups/printing-presses/wooden-presses); [American Bookbinders Museum, "Ink Balls and Printing"](https://bookbindersmuseum.org/ink-balls-and-printing/); Andrew Pettegree, Brand Luther.