Making Process

The Artisanal Process of Ru Ware Creation

 

1. Material Preparation (Weeks 1-4)

- Clay Refinement:

  • Selected from 5 specific loess layers in Henan (Fe₂O₃ content 2.1-2.8%)

  • Aged in wooden barrels for 3 lunar months with spring water

- Agate Glaze:

  • Mongolian river agate (SiO₂ 98.7%) crushed to 300-mesh powder

  • Precise 0.33% agate mixed with feldspar/quartz/plant ash

 

2. Forming Techniques (Week 5)

- Wheel Throwing:

  • 280RPM speed for wall thickness control (2.8±0.3mm)

  • "Iron Foot" base carved at 45° angle (unglazed)

- Drying:

  • 15-day controlled humidity (55% RH)

  • Infrared scan for micro-crack detection

 

3. Glazing Process (Week 6)

- Dipping:

  • 3-second immersion (0.2mm glaze thickness)

  • Double-layered application (inner/outer different formulas)

- Decoration:

  • Imperial motifs engraved with 0.1mm tungsten needles

  • Natural pine resin brushed on foot rim

 

4. Wood Firing (Week 7)

- Kiln Loading:

  • 72-piece capacity in dragon kiln (13.5m length)

  • Each piece wrapped in kaolin paper

- Firing Cycle:

  • 0-300°C: 12 hours (water removal)

  • 300-1100°C: 24 hours (quartz inversion)

  • 1100-1300°C: 36 hours (agate melting)

  • Cooling: 7 days natural (0.5°C/min)

 

5. Frost Vein Formation

- Thermal Stress:

  • Clay (α=5.4) vs glaze (α=7.1) expansion mismatch

  • Controlled cracking at 800-600°C range

- Crystallization:

  • Mullite (3Al₂O₃·2SiO₂) forms dendritic structures

  • Agate particles create "seed points" for vein branching

 

6. Quality Inspection

- Visual:

  • "Sky-after-rain" color verification (Pantone 19-4052→16-5421)

  • Frost vein density (3-5 lines/cm²)

- Acoustic:

  • 280-320Hz resonance frequency

  • ≤0.3s reverberation

- Scientific:

  • XRF test for agate content (0.30-0.35%)

  • CT scan for vein depth (0.15-0.25mm)

 

7. Aging Process

- Initial:

  • 30-day oxidation in cedar boxes

- Long-term:

  • Annual tea soaking ritual (3h in pu-erh)

  • UV light treatment (2h/year at 365nm)