SLIP DECORATION

Slip has been used for centuries to decorate pottery. Fragments of red slip on pottery aged 5000 years have been discovered in Japan, the region in which it is believed to have originated. Slip ware is the term used to describe pottery that has been treated with liquid clay ie slip, either by dipping the entire vessel and scratching it off or applying it using different techniques. Slip can be coloured or mixed with flocculant to change its viscosity. Pottery which has slip applied is most often left unglazed.

For the primitive kiln it is a method of decoration which does not require chemicals or commercial glazes. There are a variety of interesting decorating techniques using slips.

Feathering Slip is an effect thought to have been drawn by a feather. Bands of contrasting colour slip are applied using slip trailing. A soft flexible sharply pointed tool is drawn through to create a chevron pattern.

Combing is the process of drawing a fine comb through a trail of slip to create a feathered effect

Slip trailing is the most widely known method of decoration.

Liquid clay is poured into a dispenser to deliver a stream of slip onto damp or leather hard clay.

Marbling slip. Once slip is trailed over the pottery a marbling effect is created through turning or shaking the piece.

Sgraffito is the process of entirely covering the pottery with slip and then carving away areas to create a design

Resist Slip Is the process of applying slip over a wax resist design. The wax melts and disappears on firing to leave the profile design.

Slip texturing is the application of slip to create raised areas of texture

Slip Recipes

Slip is made by breaking up dried clay or greenware and soaking it in water in a zip lock bag or covered ice cream container. The result is blended or sieved until the consistency of double cream.

Coloured Slip

To create a contrast between pot and decoration a ceramic stain can be added to the slip. Available as a powder, it needs to be mixed into a paste and then added to the slip. Testing and firing a sample pot is recommended to determine the desired shade of stain.

Textured Slip

To maintain bulk once slip has dried a deflocculant can be added to allow a higher proportion of powdered clay to water. Sodium silicate is the most effective deflocculant along with soda ash.