Drying is the stage where seaweed-fiber sheets are most likely to develop defects. The gel compounds retained from algae pulp dry at a different rate than cellulose fiber — they are hygroscopic, meaning they continue to absorb and release atmospheric moisture long after the sheet appears dry to the touch. In coastal Italy, where relative humidity shifts significantly between seasons and between day and night, managing the drying environment is as important as the vat work that preceded it.
The Italian Coastal Climate
The Tyrrhenian coast — where Campania, Lazio and Tuscany meet the sea — has a Mediterranean climate with hot, relatively dry summers and mild, humid winters. Average relative humidity along the coast ranges from roughly 55–65% in July and August to 75–85% in December and January. The Amalfi coast specifically sits in a narrow valley between steep limestone cliffs that channel sea air and can trap moisture for extended periods even in summer.
Sicilian and Sardinian coastal studios experience similar seasonal patterns but with longer dry periods in summer, which generally favours faster drying. Liguria (the Italian Riviera) is consistently more humid year-round due to its northward orientation and proximity to the Alps, and drying times there are typically longer at any season.
Seasonal Working Windows
Late spring (April–June) and early autumn (September–October) offer the most stable conditions for drying seaweed-fiber sheets outdoors. Humidity is moderate, temperatures are mild, and sea breezes are consistent without being excessive. Summer (July–August) dries sheets quickly but the intensity of direct sun creates differential drying — the outer surface dries before the interior, leaving the sheet in a stressed state that promotes cockling.
Winter drying in unheated outdoor spaces is impractical on most Italian coasts. Sheets dried below 12°C take multiple days and are at risk from overnight condensation rehydrating the surface of sheets that appeared dry during the day.
Drying on Wooden Boards
The traditional method used in Amalfitan paper production involves smoothing wet sheets directly onto untreated poplar or lime wood boards. The wood draws moisture from the back face of the sheet while the exposed face dries by evaporation. This bilateral drying reduces the differential that causes cockling.
Board Preparation
Boards should be smooth but not sealed. Varnished or lacquered boards do not absorb moisture and defeat the purpose of the technique. Boards used repeatedly develop a slight surface patina from algae residue, which is normal and does not affect drying performance.
Before each use, the board surface is dampened slightly with a sponge or cloth to prevent the wet sheet from drying too rapidly at the contact face. In very dry summer conditions, a more thoroughly wetted board slows surface drying and produces flatter sheets.
Attaching the Sheet
The freshly pressed sheet is lifted from the couch felt and laid face-down onto the board. A clean, soft rubber roller or the back of the hand is used to smooth out air pockets and ensure full contact. The sheet should be centred on the board with at least 3 cm clearance on all sides — sheets dried close to the board edge often curl at the corners as they lose tension during drying.
Board Positioning
Boards are traditionally propped at a slight angle — roughly 20 to 30 degrees from vertical — against a shaded wall or rack. Vertical positioning would cause the wet sheet to sag and detach; horizontal positioning on a flat surface restricts the back-face evaporation the wood provides. The angled position allows air circulation at the board back while keeping the sheet under slight gravitational tension.
Direct sun should be avoided for algae-blend sheets specifically. The carrageenan and alginate compounds in the gel fraction degrade with prolonged UV exposure, which can cause the sheet surface to become brittle and slightly discoloured — a pale yellowish tint rather than the warm ivory of well-dried algae paper.
Drying Time
Under optimal outdoor conditions (shade, 65% relative humidity, 20°C, moderate air movement), a seaweed-blend sheet of standard handmade weight (70–90 gsm) requires eight to fourteen hours on the board before it releases naturally. Over-retaining the sheet on the board past the point of natural release causes the outer edges to over-dry and the centre to remain slightly damp — a common cause of uneven curl after the sheet has been removed.
A sheet is ready for removal when it releases from the board edges on its own and the centre no longer feels cool to the touch. The cool sensation indicates residual evaporative cooling from trapped moisture; once it is gone, the sheet is dry through its full thickness.
Indoor Drying
When outdoor conditions are unsuitable, sheets can be dried indoors on the same wooden boards, positioned near an open window or in a room with air circulation. Electric fan assistance shortens drying time but should be used at low speed and indirect angle — blowing directly onto a wet algae sheet creates uneven drying patterns visible in the finished paper as faint parallel streaks.
Heated rooms (above 25°C) dry sheets quickly but require careful monitoring. Italian artisans who work in heated winter studios typically leave a window ajar to maintain 50–60% relative humidity in the drying area, preventing the brittle cracking that can occur when gel-bearing sheets dry too rapidly in very low humidity.
Common Drying Defects
Cockling
Uneven surface waves, typically visible after the sheet has been removed from the board and stored flat. Caused by differential drying rates between the sheet surface and interior. Preventable by ensuring even air circulation and avoiding direct sun. Mild cockling can be corrected by re-dampening the sheet lightly on both faces and pressing it flat between smooth boards for 12 hours.
Edge Curl
Upward curl at the sheet edges after removal from the board. More common with high-algae-fraction blends because the gel layer at the edges dries faster than the centre. Preventable by ensuring 3 cm board clearance and by slightly dampening the board edges before attaching the sheet.
Surface Yellowing
Faint yellow tinting visible particularly in sheets dried in direct sun. Results from UV degradation of carrageenan and alginic acid compounds. Preventable by shaded drying only. Not correctable after the fact.
Tacky Surface
A slightly sticky texture that persists after apparent drying, caused by undissolved gel deposits that did not fully integrate into the fiber matrix during beating. More common when algae was beaten at too low a temperature or with insufficient time. The tacky surface typically resolves fully after 24–48 hours of open-air storage as residual moisture disperses.
Stacking and Storage
Fully dried algae-fiber sheets are interleaved with smooth absorbent paper (not acid-free tissue, which can stick) and stored flat in a dry environment. Stacking without interleaving causes the gel-bearing surfaces to bind to adjacent sheets over time, particularly in humid conditions.
Storage at 45–55% relative humidity is ideal. Sheets stored at above 70% relative humidity for extended periods will gradually re-absorb atmospheric moisture and become limp, requiring re-drying before use.
References
Historical drying methods from Amalfitan papermaking are documented at the Museo della Carta di Amalfi. Photographic records of traditional drying practices are archived in the Wikimedia Commons papermaking category.