Slip

DEFINITION

An opaque, creamy liquid made by mixing finely ground clay with water. Slip is an inevitable byproduct of working on a potter's wheel, its name having resulted from potters' use of water to keep the spinning clay slippery as it's worked. It is also used in the making of pottery to cement together parts that have been formed separately; in slip casting, and in decorating surfaces.Colored slips (also called engobes) have several distinctive attributes, but are also excellent alternatives to glazes because they are less expensive and less time consuming. They are typically made by mixing water with a claybody in use, then mixing in one or more colorants (e.g. oxides); in a proportion of dry ingredients to water that is about 1:2 by volume. Colored slips are best applied in a consistency like cream to leatherhard greenware, or a little thinner when applied to bisque. Colored slips stay put; they won't run or blur as many glazes do. Textures made in slip will remain as they're formed, instead of smoothing out as do those made with glazes. They can be applied with a brush, a slip-trailing bottle, or by dipping or spraying. Another method for using slip in making a design is called sgraffito: coat unfired clay with a colored slip, and then scratch away at parts of it to reveal the clay surface underneath.Also see ceramics, gesso, scoring, and stucco.