Hanji: The Paper That Traps Light — Part 2: Process

Part 2 of 3: Process

Papermaking begins in winter. The cold matters.

Paper mulberry is cut between December and February, when the sap has dropped and the bark fibers are at full strength. Too early and the fiber is weak; too late and new growth contaminates it. The window is narrow.

The branches — one year’s growth, thumb-thick — are steamed until the bark lifts from the wood, and workers peel it by hand while it is still warm. That gives three layers: rough outer bark, green middle, and the white inner bark that becomes paper. Only the innermost layer goes into fine hanji (한지), and getting it clean wastes most of what was cut.

White paper mulberry bark drying after washing. Only this innermost layer — stripped, rinsed, and sun-bleached — yields the cellulose fibers used in traditional hanji.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

The bark is then cooked — four to five hours simmering in an alkaline solution, traditionally lye from plant ash steeped in water — which dissolves the lignin and pectin and leaves cellulose. Modern mills often swap in sodium hydroxide; it is faster and the result is different, and the difference matters to conservators.

Boiling white bark in an alkaline bath. Four to five hours of simmering dissolves lignin and pectin, isolating the long cellulose fibers that give hanji its strength and longevity.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

After cooking, the bark is rinsed in running water for half a day, then laid underwater in sunlight to bleach naturally over five to seven days. Chemical bleach does the same job in hours and costs the paper its long-term stability.

Then the fiber gets beaten, on a stone slab, with wooden mallets. The point is not to chop the fibers but to fibrillate them — splitting microscopic branches along each strand so they will interlock later. Beaten right, the fiber turns almost slimy. Beaten too little, the paper falls apart; too much, and the fibers shorten and weaken. The middle is learned by feel.

Beaten mulberry fiber dispersed in water — Mulberry fiber after beating — dispersed thin enough to see through. Each strand measures roughly 6 to 9 millimeters, much longer than wood-pulp fiber, which is what gives the finished paper its tensile strength.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

The beaten fiber goes into a vat of water with one critical addition: dakpul (닥풀), mucilage from the root of Hibiscus manihot. It does the counterintuitive thing — instead of gluing fibers together, it holds them apart, suspended evenly through the water so they do not clump. It also slows the water draining through the screen, which buys time to build the sheet in layers, and it washes out in drying, leaving nothing behind. Synthetic substitutes behave differently, especially in humidity.

Adding beaten dak fiber into the papermaking vat — Adding beaten *dak* fiber into the vat. Mixed with *dakpul* mucilage and water, the fibers have to suspend evenly — clumping at this stage leaves thin spots that cannot be repaired later.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

Forming the sheet takes under a minute, and those seconds set how the paper lasts. The papermaker dips a flexible bamboo screen into the suspension and works it — heullimtteugi (흘림뜨기), “flowing and scooping.”

Bamboo screen and wooden frame over the fiber vat — The bamboo screen and wooden frame over the fiber vat. The screen’s flexibility allows the rocking motion of heullimtteugi — each pass deposits fibers at a different angle.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

Papermaker rocking the bamboo screen to form a sheet — Sheet formation: the screen rocked through the suspension so fibers settle in crossing layers — the motion that defines heullimtteugi.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

The screen rocks forward and back and side to side, water sheeting off the edges while fibers settle in crossing layers. Each rock lays fiber at a different angle; that is the multi-directional grain. One sheet might take three or four passes.

Freshly formed translucent hanji sheet on the bamboo screen — A freshly formed sheet on the bamboo screen. The wet paper is translucent at this stage — its final opacity and texture appear only after pressing, drying, and finishing.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

The finished sheet goes onto a growing stack, sheet directly on sheet, no spacers between them — they bond slightly and are separated later. By evening the stack might hold 400 to 500 sheets, each one a minute’s work.

Overnight the stack presses under its own weight, water draining through the pile. In the morning it goes under boards and leverage to force out the rest of the water without crushing the fiber. The pressed sheets come apart reluctantly, barely stuck, and each is moved to a heated surface — once a heated wall or floor, now often a temperature-controlled plate.

Hanji drying on a heated surface with the bamboo screen attached — *Okchun* paper drying with the bamboo screen still attached. Slow, even heat keeps the sheet from buckling or turning brittle — a full day per batch is typical for handmade hanji.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

The drying has to be slow: rapid heat shrinks the sheet unevenly and leaves it buckled and brittle. A batch takes a full day. That patience is part of why handmade hanji runs about twenty times the price of machine paper.

Dried sheets come off rough, which suits some uses. For the rest there is dochim (도침): dried sheets stacked and pounded with heavy mallets or stone. The impact compacts the fiber, smooths and densifies the surface without crushing the internal structure, and leaves a faint, almost waxy sheen. Dochim paper holds ink with sharper lines and less spread, and resists water better. Machine rollers reach similar compression with less labor; people who handle paper for a living can tell the two apart by touch.

Hanji surface after dochim pounding, showing a subtle sheen — Hanji after *dochim*. The pounding compacts the fiber surface into a faint, almost waxy sheen, making the paper more water-resistant and suited to calligraphy, window coverings, or wrapping.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

Every stage is a chance to ruin the sheet. Bark cut at the wrong time makes weak paper. Undercooking leaves lignin that yellows with age. Over-beating shortens the fiber. Uneven suspension leaves thin spots. Rushed drying buckles it. Papermakers learn these by making them — the craft moves not as written instruction but as accumulated, corrected error. A hanji-jang (한지장) may spend a decade learning to make consistently good paper and another decade refining it.

Completed hanji in three grades by thickness — Completed hanji in three grades (top to bottom): *chosanghwaji* for portraiture, *gyoji* for official documents, and *janghoji* for window coverings. Same raw material, different thickness and finishing — each calibrated for its use.— Korea Heritage Service (국가유산청), Hanjijang (한지장) documentation. KOGL Type 4.

That is the knowledge at risk. As of 2024, hanji-making is a National Intangible Cultural Heritage with designated holders. But a designation preserves a title; the technique needs practitioners, and practitioners need students willing to spend years learning what a machine approximates in minutes.

Key Terms

heullimtteugi (흘림뜨기) — the rocking sheet-formation technique
dakpul (닥풀) — hibiscus root mucilage used as a fiber dispersant
dochim (도침) — pounding/polishing finish
hanji-jang (한지장) — master papermaker (intangible cultural heritage designation)

Sources & Further Reading

Korea Heritage Service — Hanjijang (한지장) technical documentation
Hanji Industry Support Center — manufacturing process standards
Lee, Aimee. Hanji Unfurled: One Journey into Korean Papermaking
National Research Institute of Cultural Heritage — scientific analysis of traditional vs. modified hanji

This is Part 2 of a three-part series on hanji. Part 1 examined surface properties; Part 3 addresses conservation applications and contemporary relevance.

All process photographs: Korea Heritage Service (국가유산청), National Intangible Cultural Heritage — Hanjijang (한지장, Korean Paper Making). Available at heritage.go.kr. Used under Korea Open Government License (KOGL) Type 4 with attribution.