Dipping Technique
Part of Paper Making
The art of forming a paper sheet by dipping the mold into a vat of pulp suspension — controlling sheet weight, evenness, and formation.
Why This Matters
The dipping technique — drawing the mold through the vat of diluted pulp — is the central physical skill of Western-style papermaking. Every sheet you make begins with this motion. Done correctly, it deposits a uniform layer of fiber across the entire mold surface, producing a sheet of consistent thickness and even formation. Done poorly, it produces thick edges and thin centers, washboard ridges, or fiber clumps that make the finished paper nearly unusable for writing.
In a post-collapse paper mill, the ability to produce consistent, predictable sheets determines how useful your paper is to the community. A scribe copying legal documents cannot work on sheets that vary in thickness and absorbency across the surface. A mapmaker needs smooth, even paper that accepts ink without feathering. Consistent dipping technique is what makes consistent paper.
Beyond the immediate practical benefit, understanding what happens during the dip — how fiber orients, how water drains, how formation is affected by vat depth and fiber concentration — lets you troubleshoot problems and adapt your technique to different fiber types, mold sizes, and paper grades.
Understanding the Vat
The vat is a container large enough to submerge your mold completely, filled with a dilute suspension of beaten fiber in water. The correct dilution is critical. Too thick a suspension deposits too much fiber per dip and produces heavy, uneven sheets. Too thin a suspension requires multiple dips per sheet or produces paper too lightweight to be useful.
Target consistency: The suspension should look like very pale, cloudy water — translucent but not clear. If you hold a mold just below the surface and can see the mold screen clearly, the suspension is too dilute. If you cannot see the mold screen at all, it is too thick.
A practical test: scoop a small amount of pulp water in a clear jar or cup. Hold it up to light. The suspension should be translucent with fiber visible but not clumped. You should be able to read large text through it but not fine print.
Vat size: The vat must be wider and longer than your mold by at least 10 cm on each side, and deep enough to fully submerge the mold with 5 to 10 cm of water above it. A shallow vat forces awkward angles and inconsistent sheets.
Vat material: Wood, ceramic, stone, or metal all work. The vat must hold water without leaking and must be stable — it should not rock or shift when you work at it. Wooden vats should be sealed with pine pitch, beeswax, or tallow to prevent leakage.
Vat temperature: Lukewarm water (approximately body temperature) keeps fiber dispersed more uniformly than cold water and drains slightly faster through the mold. Cold water also thickens the pulp-water mixture, making even formation harder. If papermaking in cold conditions, warm the vat water before filling.
Preparing the Vat for Each Session
Before dipping, stir the vat thoroughly. Fiber settles out of suspension within minutes of inactivity. A settled vat has thick fiber on the bottom and almost pure water at the top — dipping into this deposits fiber unevenly.
Stir with a long paddle or stick, sweeping the bottom to resuspend settled fiber. The stirring motion should be circular at first, then reversed to break up any rotating current before you dip. A rotating current in the vat will cause fiber to orient in one direction, producing paper with directional weakness (it tears easily along one axis and with more difficulty across it).
After stirring, wait for major currents to subside — about 15 to 30 seconds — before dipping.
The Dipping Motion: Step by Step
Step 1: Assemble Mold and Deckle
The deckle sits on top of the mold and defines the sheet edges. It must fit snugly and squarely. Any gap between mold and deckle allows pulp to escape at the edges, creating ragged sheet edges and fiber loss. Check the fit before each dip. If the deckle slides or rocks, wedge a small folded cloth at the corner to stabilize it.
Hold the assembled mold-and-deckle with both hands at the long edges, fingers below, thumbs on top. Your grip should be firm enough to control the mold but not so tight that your hands cramp over a long production session.
Step 2: Enter the Vat at an Angle
Tilt the mold at approximately 45 degrees and enter the near end of the vat first, angling away from you. This angled entry slices into the pulp suspension rather than slapping it, which would create turbulence and uneven fiber distribution.
Submerge the mold completely — the screen surface should be 5 to 10 cm below the water surface at the lowest point of the stroke.
Step 3: Level and Draw
As the mold reaches full submersion, level it to horizontal in one smooth motion. This leveling action sweeps a wave of fiber-laden water across the mold surface, depositing fiber evenly. Draw the leveled mold forward slightly through the suspension — 3 to 5 cm of horizontal movement — to encourage even fiber distribution.
Do not move too slowly (fiber begins settling before the full sheet is deposited) or too quickly (the forward motion creates a wave that piles fiber at the leading edge).
Step 4: Lift Smoothly and Quickly
Lift the mold out of the vat in a single smooth motion, keeping it level. The moment the mold breaks the water surface, fiber begins depositing. If you tilt the mold as you lift, fiber slides toward the low end, creating thick edges and thin centers.
As the mold clears the water surface completely, give it one or two small horizontal shaking motions — forward-back, then side-to-side, a few centimeters of travel each. This “shake” disperses any remaining fiber clumps and distributes fiber uniformly across the sheet. Japanese papermakers use a more vigorous continuous shaking (called the nagashi-zuki technique) for very thin, even sheets.
Step 5: Drain
Hold the mold level and allow water to drain through the screen. You will see it draining initially in fast streams, then slowing to a steady seep, then nearly stopping. Active draining takes 15 to 45 seconds depending on fiber length, sheet weight, and temperature.
Do not disturb the mold during this draining period. The fiber mat is still mobile when very wet — bumping or jostling will shift fiber and disrupt the even formation you just created.
Reading the Sheet: Diagnosing Problems
Hold the drained mold up to a light source. A well-formed sheet shows:
- Even translucency across the entire surface
- No clumps (dark spots with thick fiber concentration)
- No holes (transparent spots with no fiber)
- Straight edges at the deckle boundaries
Common defects and their causes:
| Defect | Appearance | Cause | Fix |
|---|---|---|---|
| Ridges | Parallel stripes of thick and thin | Mold drawn too quickly | Slow the draw stroke |
| Thick center, thin edges | Dark center, pale edges | Mold held horizontal before leveling | Level fully before lift |
| Thick one edge | One edge dark | Tilted during lift | Keep mold level on exit |
| Clumps | Dark patches | Under-beaten fiber | More beating |
| Holes | Pale spots | Over-dilute suspension | Add more pulp |
| Bubbles | Circular thin spots | Soap contamination or air | Rinse equipment |
Adjusting Sheet Weight
Sheet weight — how heavy and thick the finished paper is — depends on pulp concentration and how much fiber you deposit per dip.
To increase sheet weight: Add more pulp to the vat (thicker suspension) or lift the mold more slowly to let more fiber settle onto it.
To decrease sheet weight: Dilute the vat with additional water, or lift the mold more quickly.
Aim for consistency across a batch. After the first few sheets of any session, you will develop a feel for how much fiber you are picking up. If sheets seem too heavy, add water and stir. If too light, add more pulp slurry.
Multiple Dips for Heavy Paper
For thick paper — suitable for book covers, durable documents, or wrapping — a single dip may not deposit enough fiber. You can make multiple dips: couch the first sheet, then immediately re-dip the same felt and couch again on top of the first sheet. Two layers pressed together produce a thicker, stronger sheet. However, two separate sheets pressed together after independent formation tend to delaminate — the double dip onto the same couching surface works better.
Surface Turbulence Management
In a busy vat after many dips, fiber concentration drops (it is being removed with each sheet) and vat turbulence accumulates. Replenish the vat by adding pulp slurry from a holding bucket. Stir and rest before continuing. Ideally, maintain a relatively constant vat concentration rather than letting it deplete completely and refilling all at once.
After every 10 to 15 sheets, give the vat a full stir and a full 30-second rest before continuing. Fatigue from continuous dipping often leads to rushing this rest period — the resulting sheets are always less even.
Vat Maintenance Between Sessions
At the end of a production session, remove all pulp from the vat. Pulp left standing overnight begins fermenting in warm weather, producing acids that weaken fiber. The vat itself can harbor mold and bacteria that contaminate future batches.
Rinse the vat thoroughly with fresh water. Scrub the walls and bottom to remove settled fiber. Store the drained vat dry if possible, or leave it filled with clean water if you plan to continue the next day.
Dipping is a skill that takes perhaps 100 sheets before it feels natural and several hundred before it becomes automatic. Keep a few sheets from each early session as a record of your progress — the improvement in formation from your first sheet to your fiftieth is striking, and concrete evidence of mastery is itself worth preserving.