Raku Firing: A Tale of Serenity and Artistry


In the heart of Japanese ceramics lies the word "raku" (楽), embodying comfort, relaxation, and pleasantness. Beyond its linguistic charm, Raku holds a deeper significance as the name of a Kyoto suburb where, in the mid-16th century, artisan Chojiro birthed a distinctive ceramic style known as raku-yaki (楽焼).

Crafted from clay extracted in the serene surroundings of this suburb, Chojiro's creation became synonymous with tea bowls commissioned by the tea master Sen-no-Rikyu (1522-1591). As the Muromachi period (1336-1573) closed, the tea ceremony embraced Japanese ceramics, or "wamono" (和物), with Sen-no-Rikyu at its forefront.

"Wabi" (侘), meaning simplicity, paired with the tea ceremony, defines beauty derived from simplicity—a principle by the master. This led to radical simplification in ceramics and utensils, focusing on spiritual exchange.

Chojiro, son of Ameya, brought the "sancai" ceramic technique from the Tang Dynasty in China. Crafting a tea bowl embodying wabi-cha's essence, he birthed a new aesthetic, turning each object into a unique masterpiece.

Sen-no-Rikyu grasped Chojiro's work, a manifestation of grace and simplicity that expressed the aesthetic and spiritual essence of a vital ritual. The name Raku became the surname and seal of a lineage still active in Japan, now in its 16th generation.

Through these masterpieces, we journey into the mystery of "isshisoden" (一子相伝), the oral transmission of art's secrets. A continuity emerges, characterizing the entire Raku artistic production. Each successor becomes a voice of their era, offering a fresh face while maintaining a strong dialogue with the past.

Even today, master ceramists transmit this art orally, guarding crafting and handling secrets. Elements like Earth, Air, Water, and Fire, coupled with human creativity and tradition, take center stage, speaking to us of nature and an immeasurable inner richness.


Understanding Raku Glazing: The Basics

At its core, Raku glazing is about applying a carefully formulated mixture of chemicals onto a ceramic surface. This glaze, composed of silica, feldspar, and various metal oxides, undergoes a profound metamorphosis during the firing process. The result is a visually stunning fusion of colors and patterns.


Chemistry and Aesthetics: Crafting the Green Metal Effect Glaze

In the heart of Raku glazing lies the alchemy of creating distinct glazes. Our signature green metal effect glaze, inspired by traditional Chinese and Japanese aesthetics, involves a precise recipe. Combining copper carbonate, iron oxide, rutile, and a touch of feldspar in specific proportions, this formulation yields a glaze that dances between deep greens and metallic hues during the firing process. The addition of feldspar enhances the glaze's fluidity and adherence, contributing to the overall aesthetic appeal.

Laabmilano Green Metal Effect Glaze Recipe:

  • Green Metallic Raku Glaze Recipe:
  • Copper Carbonate: 5-7% by weight (provides green color)
  • Rutile: 2-3% by weight (contributes to metallic effects)
  • Cobalt Carbonate: 1-2% by weight (enhances depth and richness)


This carefully crafted combination not only produces a visually captivating green metal effect but also ensures a harmonious interaction with the firing process. As the glaze undergoes transformation in the kiln, the copper carbonate introduces dynamic greens, while the iron oxide and rutile contribute to the mesmerizing metallic qualities. The incorporation of feldspar acts as a stabilizing agent, promoting uniform application and adherence to the ceramic surface.

Feel free to experiment with these proportions to achieve variations in color intensity and surface texture. The artistry of Raku glazing, coupled with the precision of our green metal effect glaze recipe, embodies the essence of Laabmilano's commitment to creating unique and culturally inspired ceramic masterpieces.


Choosing the Right Glazes: Chemistry and Aesthetics

The selection of glazes is a critical step in the Raku glazing process. Each component in the glaze plays a specific role, from providing color to influencing the melting point. Copper oxide, for instance, can introduce reds and greens, while cobalt carbonate contributes blues.

Artists often blend different glazes to achieve unique effects. The interaction between these compounds and the volatile firing environment contributes to the unpredictable beauty of Raku glazing.

The Firing Process: Where Chemistry Meets Artistry

The firing process in Raku glazing is a carefully orchestrated sequence. Once glazed pieces enter the kiln, they experience a rapid temperature climb. The glazes melt, transforming into a glassy surface. The critical juncture is the moment of extraction, where red-hot pottery meets the reduction chamber.

The reduction chamber, often a metal container filled with combustible materials like sawdust or newspaper, initiates a reduction atmosphere. This oxygen-starved environment induces chemical reactions, altering the colors and patterns on the glazed surface. The science of reduction is pivotal in achieving the coveted metallic and iridescent effects seen in Raku-fired pieces.


Factors Influencing Raku Glaze Effects: A Balancing Act

Several factors influence the final glaze effects in Raku firing. The timing and duration of reduction, the choice of combustible material, and even the placement of the piece within the reduction chamber all contribute to the alchemical transformation.

The speed at which the kiln is cooled post-firing adds another layer of complexity. Rapid cooling solidifies the unique patterns, introducing an element of unpredictability that defines Raku glazing.


Technical Considerations: Thermal Shock and Crackle Glazes

The rapid cooling characteristic of Raku firing introduces an inherent risk: thermal shock. The stark temperature contrast between the hot kiln and the reduction chamber can lead to cracks. Understanding the clay body's composition and employing proper bisque-firing techniques become crucial in mitigating this risk.

Crackle glazes, a hallmark of Raku, involve intentionally creating fine cracks in the glaze surface. This effect is achieved by formulating glazes with a high thermal expansion coefficient. As the piece cools rapidly, the glaze contracts more than the clay, resulting in controlled cracking.

Conclusion: The Technical Poetry of Raku Glazing

In conclusion, Raku glazing is not merely an art form; it's a technical poetry that weaves together chemistry, physics, and artistic intuition. As you explore the Raku-glazed masterpieces at www.laabmilano.com, envision the meticulous dance of molecules and the controlled chaos of reduction that give birth to each captivating piece. Raku glazing stands as a testament to the fusion of technical mastery and creative expression, elevating ceramics into a realm where science and art entwine in harmonious splendor.