Composition: Finely ground white clays are combined with medium grog, which increases porosity and reduces cracking, shrinkage and warping.

Modeling: AMACO® Off White Clay No. 27 is recommended for Raku. It is excellent for throwing, hand building and slabs. The high content of grog makes this clay very forgiving. Raku pieces are shock resistant when reduced whether they are thrown or slab built and breakage is almost completely eliminated. Large Raku tiles can be made without fear of warping and with little care in drying. When bisque is fired to cone 05, the result is a piece that is strong and shock resistant at the same time. You don?t have to fire a soft bisque even when you want to Raku the piece. When used in Raku, unglazed fired clay will turn dark gray to black depending on the intensity of the reduction.

You can also use AMACO® cone 06-05 glazes for Raku on clay formula No.27 by bringing glaze up to maturity, then allowing the kiln to cool to about 1700ºF, 927 ºC before removing the pieces from the kiln. Always make sure the kiln is turned off before you pull the pieces out.

The CR- Crackle glazes are especially good for Raku because you can underfire them to Raku temperature with good results, plus they develop a good crackle that looks great in reduction.

AMACO® Off White Clay No. 27 is also excellent for sculpture. Sculptures can be made solid. They can be modeled by adding and taking off clay, although it is always a good idea to be careful not to trap air in the modeling process even though this clay is very forgiving. While some other clays may explode in the kiln from trapped air, this clay has a much smaller chance of doing so. After the sculpture is completed, it can be emptied on the inside leaving a more or less uniform thickness in the clay shell.

Another way of sculpting is building the form by using slabs of clay. These can be shaped and put together by using slurry made from the same clay or by using vinegar on the seams and pushing them together. Adding clay on the surface can be done if needed. This technique will result in a sculpture that is already emptied on the inside and have less chance of breakage because the wall thickness of the piece is more uniform.

Firing: AMACO® Off White Clay No. 27 has a wide firing range from Cone 05-6 (1911º - 2269ºF, 1044º-1243ºC). At Cone 04, bisque is white with some black specks. Shrinkage is 7% and absorption is 16%. At Cone 5, bisque is a light buff color with very few specks and has shrinkage of 9% and absorption of 10%. Due to variations in the natural color of raw materials, clay formula No. 27 will vary in color from light buff to a dark gray in its raw form. Fired clay will also vary from off white to light buff. This difference, however, will not affect its workability or characteristics.

Decoration: Any of the Cone 06-05 AMACO® glazes, all of the AMACO® decorating colors, as well as the AMACO® cone 5-6 glazes may be selected for use with this clay.