After a sheet is formed on the mould, it still contains a large quantity of water — typically more than 90% of its total weight at the moment of lifting from the vat. The pressing and drying stages remove this water progressively, first through mechanical compression and then through evaporation. Each step must be executed carefully to avoid surface defects, uneven thickness or warping in the finished sheet.
Couching: Transferring the Wet Sheet
Couching is the act of transferring a freshly formed sheet from the mould surface onto a damp felt. The word comes from the French coucher — to lay down. At the moment of transfer, the sheet is fragile and can tear if insufficient fibre-to-felt contact is made or if the motion is uneven.
The Felt
Felts used in hand-papermaking are typically woven from wool or synthetic fibres. Wool felts have a slight texture that allows water to wick away from the sheet surface. The felt must be damp — not wet — at the moment of contact; a dry felt draws water too quickly from the sheet edge, causing it to stick and tear.
Traditional Polish workshops used undyed wool felts that were rinsed and squeezed before each couching cycle. Contemporary practitioners often substitute synthetic felts, which are easier to maintain and more resistant to mildew during extended damp storage.
The Couching Motion
The papermaker places the mould face-down onto the felt surface at one end and rolls it forward in a single, continuous motion — pressing the mould wire against the felt so that the wet sheet transfers completely. Lifting the mould cleanly at the end of the motion requires experience: any hesitation leaves a double-impression or partial attachment.
Each transferred sheet is covered with a new felt, and the sequence is repeated. The resulting stack — alternating paper sheets and felts — is called a "post." A post typically contains fifteen to twenty sheets before pressing begins, though this varies with available felt supply and sheet thickness.
Pressing: Removing Water Under Compression
A post of felted sheets is placed in a press and subjected to gradually increasing pressure to expel water. The amount of pressure applied, and the rate at which it increases, affects sheet density, surface texture and dimensional stability after drying.
Screw Press
The most common press type in traditional and small-scale contemporary workshops is the wooden or iron screw press. Pressure is applied manually by turning a large horizontal arm attached to the screw. The operator increases pressure incrementally over five to fifteen minutes, allowing water to flow out through the felts without forcing fibres out of alignment. Over-rapid pressing can cause "felting marks" on the sheet surface — impressions of the felt texture — or force fibres into a denser, less uniform mat.
The historic screw press at Duszniki-Zdrój operates on the same mechanical principle as 17th-century presses documented in Central European mill inventories, though the materials of the housing and press boards have been renewed over time.
Hydraulic Press
Hydraulic presses allow more precise control of applied pressure. They are used in contemporary workshops producing paper for conservation or art purposes where consistent sheet density is required across a large batch. The principle is identical to the screw press but the force is generated by a hydraulic ram rather than a threaded shaft.
Post pressing vs. pack pressing: Some workshops perform a first pressing of the full post, then separate the felts and sheets, re-stack the sheets together without felts, and press again. This "pack pressing" step further consolidates the sheet and can improve surface smoothness. It is not universal and depends on the paper's intended use.
Exchanging Felts Mid-Press
If a press cycle is extended or multiple pressing passes are desired, the saturated felts can be removed, wrung out or replaced with fresh damp felts, and the post rebuilt and pressed again. This exchange reduces the water remaining in the sheets more efficiently than a single long press. Felt exchange between pressing cycles is common in workshops producing heavier-weight papers above 120 g/m².
Separating Sheets from Felts
After the final pressing cycle, sheets are separated from their felts. If the paper has been pressed to a low residual moisture content, separation is straightforward — the sheet peels cleanly from the felt without tearing. If pressing was insufficient, sheets may adhere to the felt surface and require careful handling.
Sheets are set aside in a flat pile with boards between groups of two or three to prevent sticking. At this stage, the paper is still damp — typically containing 40–60% water by weight — and remains highly susceptible to deformation if handled carelessly.
Drying Methods
Drying is the final water-removal stage. How a sheet dries — the rate, temperature and whether it is restrained or free to move — determines its final flatness, surface quality and dimensional stability.
Board Drying
Wet sheets are brushed onto smooth wooden boards — traditionally polished hardwood — and pressed flat by hand. As the sheet dries against the board, it shrinks slightly; the board surface prevents cockling. The sheet is then carefully peeled off once fully dry. Board drying produces a smooth, flat surface on the board-contact face and a more open texture on the exposed face.
In Polish workshops, lime wood and alder have historically been used for drying boards due to their smooth, close-grained surfaces. Contemporary boards are sometimes made from coated MDF or acrylic sheet.
Line or Loft Drying
Sheets can also be hung over wooden poles or cotton lines in a loft or ventilated drying room. This method allows both faces to dry at similar rates, which reduces the differential shrinkage that causes cockling. However, sheets must be hung without sharp creases, and air movement must be even across the drying space to prevent localised wet spots that dry unevenly.
Traditional Polish mill lofts were designed with adjustable shutters on opposing walls to allow cross-ventilation in summer and restricted airflow in winter. This level of environmental control significantly affected drying time and sheet quality across seasons.
Constrained Drying
For papers that must remain very flat — such as those intended for printing or bookbinding — sheets are sometimes dried under light compression between smooth boards or sheets of glass. This restrained drying prevents any shrinkage-driven movement in the plane of the sheet. It produces the flattest result but is labour-intensive and requires an adequate supply of smooth boards or glass panels.
Drying temperature: Elevated temperature accelerates drying but can cause uneven moisture gradients across the sheet thickness, leading to curling. Ambient-temperature drying in a ventilated room — typically 18°C to 22°C — is standard practice in Polish hand-papermaking workshops for papers where flatness is a priority.
Post-Drying Finishing
Fully dried sheets may undergo additional surface treatments before use. Surface sizing with animal glue or starch reduces absorbency and improves writing or printing performance. The sizing bath — a warm solution of dissolved glue or cooked starch — is prepared separately, and each sheet is drawn through it by hand or with tongs, then re-dried.
Calendering — passing sheets between polished metal or stone rollers — compresses the surface fibres and reduces texture variation. It is optional and is most often applied to papers destined for copperplate printing or fine art drawing where a smooth surface is required.
After all finishing is complete, sheets are trimmed to final dimensions, sorted by weight and surface quality, and stored flat in a low-humidity environment. Paper made from rag fibres with neutral or alkaline sizing is stable indefinitely under appropriate storage conditions, which is one reason rag-based handmade papers are used in archival book conservation.
