New · Raku lab
Fast firing, a glowing piece pulled from the kiln, smoke drawing on the clay. Learn the basics, find raku recipes built for materials sold in Brazil and follow the tests in our studio.
🏺 Raku is decorative: the piece stays porous and is not for food.
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A short firing (1–3 h) up to ~900–1000 °C. Once the glaze matures, the piece is pulled glowing from the kiln into a can with sawdust: smoke blackens the bare clay and seeps into the glaze cracks.
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It must survive thermal shock: a well-grogged body, even wall thickness and a low bisque so the piece stays porous.
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The glaze goes through stages: it bubbles, looks like lava, pits, and finally smooths into a shine like water on ice. That is when you open the kiln. In raku you judge by eye more than by cone.
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A small metal can, a little material on the bottom, the piece inside and the lid on as soon as it catches (within ~15 s). Intensity comes from speed, not from more sawdust. Open the can face away: the air makes the fire flare.
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Outdoors, away from windows. Heat gloves, cotton clothes, face shield and closed shoes. No treated wood, plywood or particle board in the reduction: the glues release toxic fumes.
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The body stays porous and raku glazes are unstable on purpose. A raku piece is decorative: never for food or drink.
Each recipe shows the expected effect (an AI illustration) and, next to it, the real result once the studio test is done.
Crackle · Beginner · Raku, ~950–1000 °C
Will be tested in the studio
Photos of the real result will show up here.
Glossy clear glaze that crazes as it cools; smoke from the reduction gets into the cracks and draws a black network over the clay. Highest contrast on a white body.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Crackle · Beginner · Raku, ~950–1000 °C
Will be tested in the studio
Photos of the real result will show up here.
The raku classic: milky white with a bold black crackle that also covers dark clays.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Copper · Intermediate · Raku, ~950–1000 °C
Will be tested in the studio
Photos of the real result will show up here.
One glaze, two worlds: strong reduction in a tight can gives copper red and metallic luster; if air gets in (or you open early), crackled turquoise. Every piece is different.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Metallic · Intermediate · Raku, ~950–1000 °C
Will be tested in the studio
Photos of the real result will show up here.
Deep black that, under strong reduction, picks up metallic and iridescent flashes (blue, purple, bronze) where it is thicker.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Matte copper · Intermediate · ~1010 °C (use a pyrometer)
Will be tested in the studio
Photos of the real result will show up here.
Almost pure copper, no gloss: the piece comes out flashing red, orange, purple, blue and green, like weathered metal. The effect comes from the firing more than the chemistry.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Naked raku · Intermediate · ~930–980 °C
Will be tested in the studio
Photos of the real result will show up here.
A layer that peels off after firing: underneath, the clay stays pale where the glaze protected it and turns black where smoke got through the cracks — fine, ink-like lines.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Naked raku · Intermediate · ~930–980 °C
Will be tested in the studio
Photos of the real result will show up here.
A heavily crazing glaze that comes off with the slip — it is there only to draw smoke lines on the clay.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Finish · Beginner · Up to ~1000 °C (loses its sheen above)
Will be tested in the studio
Photos of the real result will show up here.
An ultra-fine clay coat that, buffed with a soft cloth, turns satin without glaze. In raku it takes smoke softly — ideal base for naked raku and horsehair.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Base · Beginner · Ingredient — replaces Gerstley Borate
Gerstley Borate is the flux behind almost every classic raku glaze and is hard to find in Brazil. This blend matches its chemistry (boron, calcium, magnesium and sodium) with locally sold materials. Mix 1 kg dry and use it in place of Gerstley, same amount.
🔒 Full recipe for subscribers
Ingredients, proportions and the firing walkthrough are unlocked on any paid plan.
Fundamentals studied in Steven Branfman, Mastering Raku (Lark Books, 2009). The recipes on this page are Keramoslab versions, recalculated for materials sold in Brazil and tested in our studio.