Raku is a traditional Japanese pottery technique that has been used for centuries to create surfaces that are rich in character and full of variation. It originated in the sixteenth century, and was first used to craft tea bowls for the Japanese tea ceremony. These original pieces were shaped by hand rather than on a potter’s wheel, with a focus on simplicity and naturalness.
The word “Raku” is often translated as happiness in the accident. That phrase captures the entire philosophy: each piece is shaped by fire, smoke, and chance, so no two outcomes ever match exactly.
Over time, Raku evolved into a modern firing method adopted around the world. While traditional Japanese Raku cools pieces in open air, Western Raku introduces a dramatic post firing reduction step that creates the bold crackles and smoke patterns many potters now associate with the style.
Historical Raku Pottery
Early Japanese Raku was made mainly for tea ceremonies. Potters used either red earthenware clay with a clear glaze or stoneware clay with a dark glaze. These pieces were bisque fired, glazed, then fired again and removed from the kiln while hot. They were cooled quickly in the open air, which encouraged the glaze to craze.
In the tea ceremony, the soft sound of a crazed glaze was considered more calming than the sharper sound produced by an uncracked surface. That preference helped shape the tradition and is one of the reasons why crazing remains closely linked to Raku today.
Modern Raku Pottery
Raku spread to Western potters in the early twentieth century, especially following Bernard Leach’s exposure to Raku gatherings in Japan. Leach helped introduce the process to Europe, and it later gained a significant following in the United States.
In the 1960s, American ceramicist Paul Soldner developed an approach that defined modern Western Raku. He introduced the reduction chamber stage, where hot pottery is placed into combustible material so that smoke and fire dramatically alter the glaze and clay surface. His experiments encouraged potters to embrace accidents rather than prevent them, opening the door to the highly unpredictable Raku effects seen today.
What Makes Raku Distinct
Raku differs from standard kiln firing in several important ways:
• It uses low glaze firing temperatures
• The kiln is heated very quickly
• Red hot pottery is removed from the kiln while the glaze is still molten
• Thermal shock creates deliberate crazing
• Reduction chambers create blackened clay and strong colour variation
• Results are unpredictable
• Finished pieces are usually decorative only because Raku ware is porous and fragile
These qualities give Raku one of the fastest firing cycles in ceramics. A piece can go from bisque fired to fully glazed and finished in under an hour.
How Raku Firing Works
Step 1: Bisque fire
Raku ware begins like any other pottery. Pieces are shaped, dried, and bisque fired to strengthen the clay. Electric kilns are commonly used for this stage.
Step 2: Apply Raku glaze
Raku glazes melt at low temperatures, usually cone 06 or near that range. A thin coat melts quickly and produces clearer effects. Resist materials such as wax can be added to create patterns.
Step 3: Load the kiln
Arrange pieces with space between them so heat can move freely. Many potters use small gas fired Raku kilns because they heat rapidly and can be used outdoors.
Step 4: Heat to glaze maturity
Raku firing temperatures typically fall between 1470 and 1850 degrees Fahrenheit. Once the glaze appears glossy and liquid, the piece is ready.
Step 5: Remove the piece while red hot
Wearing heat proof gloves, use metal tongs to lift the glowing piece from the kiln. The glaze will still be molten.
Step 6: Reduction
Place the hot piece into a container filled with combustible materials such as sawdust, leaves, straw, or shredded newspaper. The material ignites immediately. Place a lid on the container so the flames consume the oxygen. This reduced atmosphere changes metal oxides in the glaze and creates vibrant colours and metallic effects.
Step 7: Cooling
After a few minutes, open the container carefully. Use tongs to remove the hot pottery, then cool it in open air or submerge it in water. Once cool, soot and ash can be cleaned away to reveal the final surface.
Eastern and Western Raku
Both Eastern and Western Raku begin by heating pottery rapidly in a kiln. The difference is what happens after the glaze melts.
Western Raku
• Includes a reduction stage in combustibles
• Produces smoke blackening, metallic effects, bright copper tones, and strong crackle patterns
• More dramatic variation from pot to pot
Obvara
A European variation called Obvara uses a mixture of yeast, flour, and water. Hot pottery is dipped into the mixture and then into water, creating soft, organic patterns unlike standard Raku reduction surfaces.
Glazing for Raku
Raku glazes are formulated to melt quickly. They can be brushed, dipped, poured, or sprayed. Many potters use resist techniques to create patterns or leave certain areas bare to catch smoke.
Some glazes designed for electric kilns are made to mimic the appearance of Raku, including crazing and smoky textures, without needing a reduction stage. A high fire stoneware glaze recipe that resembles Raku effects may use flint, feldspar, china clay, wood ash, and whiting to create a crackled surface with subtle variation.
Clay for Raku
Raku does not require special clay. The main requirement is that the clay must withstand thermal shock. Clays that contain grog, sand, or other coarse particles handle the rapid temperature changes well.
Many stoneware clays work perfectly for Raku because they remain porous when fired at low temperatures. Pieces may be wheel thrown, hand built, or sculpted. The method is flexible, as long as the clay can handle the stress of fast heating and cooling.
Safety When Firing Raku
Raku firing involves very high heat and large amounts of smoke, so safety is essential.
• Always fire outdoors
• Wear heat proof gloves, cotton clothing, long sleeves, and closed shoes
• Use proper tongs
• Keep water buckets nearby but away from the kiln opening
• Work with at least three people if possible
• Be cautious when opening reduction containers as hot smoke can rise quickly
• Avoid synthetic clothing that can melt
Following these precautions keeps the process controlled and reduces burn risks.
Kilns Suitable for Raku
Many kilns can be used for Raku, depending on your setup.
Gas fired Raku kilns
These are the most traditional choice for modern Raku because they heat quickly and can be used outdoors. Examples include small portable Raku kilns and larger studio models.
Electric kilns
Electric kilns are commonly used for bisque firing. Some potters also glaze fire Raku in electric kilns, although most still prefer gas for the final firing.
Popular models mentioned across sources
• RODERVELD Raku Kiln
• Cress GK2
• Olympic 1823 FLE
• Olympic 129FLE
• Paragon Max 119
Beginner potters often start with a portable kiln. Larger kilns allow more complex firing cycles and can handle larger pieces.
How to Recognize Raku Pottery
Raku pottery has several unmistakable features:
• Bright turquoise, copper red, and deep blue glazes
• Metallic or iridescent finishes
• Heavy crackle patterns
• Blackened unglazed clay from smoke
• Soft or porous clay body
• Surfaces that vary dramatically piece to piece
Because of its porosity and rapid firing method, Raku is usually decorative rather than functional.
Summary
Raku firing combines ancient tradition with a modern spirit of experimentation. The fast firing cycle, the dramatic moment when glowing pieces are lifted from the kiln, and the way fire and smoke transform the glaze make each piece entirely unique.
Whether you follow the Eastern approach or the more dramatic Western reduction method, Raku offers a rewarding process that balances technique with spontaneity. Once you understand the fundamentals, it becomes a creative way to explore texture, colour, and the unpredictable beauty that comes from working closely with fire.