View Larger Image A raku glaze is any glaze you use in the raku method. The key to success is understanding the raku firing process and the ability to predict how a particular glaze reacts to the process. Shown: Brushed stoneware glaze under clear raku glaze.

January 14, 2008

Technique of the Week: The Raku Method

by Steven Branfman | Read Comments (4)

Raku as practiced in the West is a low-fire method in which we quickly heat the ware, remove the ware from the kiln when the glaze has melted, and perform some type of post-firing process to the piece. The post-firing phase is usually an immersion in an organic combustible material to affect the final outcome on the glaze and the raw clay. Deciding when the glaze has melted takes practice and is best done by observation, though many potters use pyrometers to aid in making that decision. Raku is exciting, often unpredictable to the novice and fun to do.

Dedicated Raku Glazes
Glazes specifically designed for raku fall into two categories—homemade and commercially prepared. If you mix your own, you can find recipes and information on the Internet, through friends, or in books. The advantage of using commercial glazes is that you are given instruction on how to use the glaze, you have a sample of the fired glaze to help guide your results, and the formulation (although not the results!) will be consistent time after time.

Low-Fire Glazes
Glazes used in the raku process need not be “raku” glazes at all. At its core, raku is a low-temperature firing method. Any glaze that is formulated to fire at the low temperature of raku can be used. Most raku is done in the Cone 010-06 range.

High-Fire Glazes
With greater understanding of the raku process, even mid-range and high-fire glazes can be used in the low-temperature range of raku. Try using your regular stoneware glazes as slips. Over the glaze, apply a clear or white raku or other low temperature glaze. The low-temperature glaze causes the high-fire glaze to melt giving you a new palette of colors to work with.

Other Glazes
In addition to glazes, slips, engobes, underglazes, overglazes, chinapaints, and underglazepencils are all viable in the raku process. Keep in mind that no matter what type of glaze or decorative material you use, raku is inherently unsafe for use as domestic ware. Be safe, and think of your raku ware as decorative and not functional.

About the Author
Steven Branfman is founder and director of the Potters Shop and School in Needham, Massachusetts, a workspace, school, gallery, bookstore and his studio. You can read Steven's article "What's a Raku Glaze?" in Raku, Pit and Barrel.