Earth Pigments & Shell White

What They Are

Earth pigments are naturally occurring iron oxide pigments derived from mineral deposits in the earth. Their colour is determined primarily by the form of iron oxide present:

• Yellow ochre (황토): Hydrated iron oxide (goethite, FeO·OH). Yellow to amber. Korean yellow ochre (황토) from 고성 (Goseong) and 보령 (Boryeong) is prized for its warmth and purity.
• Red ochre / burnt ochre: Anhydrous iron oxide (hematite, Fe₂O₃). Red to orange-red. Produced by heating yellow ochre.
• Umber (raw / burnt): Iron oxide + manganese dioxide. Raw umber: cool green-brown. Burnt umber: warm red-brown.
• Sienna (raw / burnt): Iron oxide + clay. Raw sienna: transparent yellow-brown. Burnt sienna: orange-red.
• Noerok (뇌록): Traditional Korean green — not a true earth pigment but classified with earth tones. Malachite-based (copper carbonate). The characteristic soft, slightly greyed green of Korean traditional painting.

토채 in Korean Traditional Painting

Tochae (토채) refers to Korean earth pigments — ground mineral earth used directly as colourant. The specific sourcing of earth from particular regions is significant: hwangto (황토, yellow ochre) from Goseong (고성) has different warmth and tone than Boryeong (보령) hwangto. These regional variations are part of the material memory of Korean painting tradition.

Tochae (토채, earth pigment) is used as:

• Background wash for warming paper or silk
• Direct colour in figurative and landscape painting
• Mixed with 지당 (titanium white) for warm, slightly muted whites

호분 — Shell White

Hobun (호분, 胡粉) is one of the most important and distinctive materials in Korean and Japanese traditional painting. Made from ground oyster, clam, or scallop shells, it has been aged on a seashore for a minimum of 15 years so that the salt content dissipates — leaving the calcium carbonate neutral (pH approximately 7).

Shell white that has not been fully weathered retains salt and alkalinity, which can react with other pigments and damage paper or silk over time. True aged 호분 is matte, dense, and brilliant — its white is warmer and less stark than titanium white or lead white.

Hobun gyeongdan (호분 경단, shell white balls): hobun (호분, shell white) formed into small balls (경단) — increases adhesive quality. Used for white grounds and strong white areas in Korean traditional painting.

Sizing ratios for 호분: Mix with warmed agio solution (same as seokchae (석채, stone pigment)). Apply in multiple thin layers for full opacity. The back-coating technique (baeche / 배채, back-coating) — applying 호분 to the back of the silk — builds depth that reads through the front, creating a luminous rather than flat white.

Preparation

Earth pigments used directly often need levigation (washing in water to separate fine particles from coarse grit). For traditional use:

1. Grind in mortar and pestle to desired fineness.
2. Mix with water; allow coarse particles to settle; pour off the fine suspension.
3. Dry the fine pigment.
4. Mix with agio binder for application.

Tools & Safety

Mortar and pestle (약사발), mixing dishes, dedicated brushes. Earth pigments are non-toxic. Note: some historical earth pigments contain trace heavy metals (manganese in umber) — standard studio precautions apply (avoid ingestion, wash hands).

Jay's Studio Note

황토의 warmth is something that titanium white or synthetic ochre cannot fully replicate — it has a specific quality that connects to the ground it came from. In the Bonghwa project (planned — 봉화, Jay's family's agricultural land), using local 황토 from the site as pigment is part of the concept: the earth of a specific place becomes the colour of a specific work.

References

• 장미님 워크숍, Seoul 2026
• 석채장 견학 (stone pigment workshop visit, planned)
• 가일 전통 안료 (Korean traditional pigment supplier)