Terms, Glazes, Finishes and Media Explained.

Terra Sigilata – Terra sigilata translates quite literally as sealed earth.'Terra sigillata' can be made from most clay, mixed as a very thin liquid slip and then settled to separate out only the finest particles, which is used as terra sigillata. It is applied to unfired clay surfaces. "Terra sig" can be polished with a soft cloth or brush to achieve a shine ranging from a smooth silky lustre to a high gloss. This process has been around since around the 1st century and is a very distinct type of pottery made by the Romans.

Raku - Raku generally involves removing pottery from the kiln while at bright red heat and placing it into containers with combustible materials. Once the materials ignite, the containers are closed. This produces an intense reduction atmosphere which affects the colours and glazes and clay bodies. The drastic thermal shock also produces cracking (known as crackling since it is deliberate). The original Japanese style of raku is an outgrowth from Buddhist influences in life and especially in the tea ceremony. 

Nerikomi - Nerikomi, ("kneading") is a technique for creating Japanese pottery agateware. The name derives from the traditional technique of creating patterns with colouredclay.You may also hear it referred to as neriage.Nerikomi involves slabs of different clays or clays colored with stains or oxides, which are stacked, folded, pressed into logs, sliced, and arranged to form a vessel. In this way, the numerous stacked coloured layers appear as fine patterns and lines embedded in a surrounding color in the finished vessel.

Engobe - French for slip, engobe is a clay slip which is coloured with metal oxides or stains, has added silica and is used for coating the surface of a form either before or after bisque firing.

Washi Paper - Washi is traditional Japanese paper. The word "washi" comes from wa meaning 'Japanese' and shi meaning 'paper'. The term describes paper that uses local fiber, is processed by hand and made in the traditional manner. Washi is often made using fibers from the inner bark of the Gampi tree, the mitsumata shrub, or the paper mulberry (kōzo) bush.  Washi paper is typically stronger than paper made from wood pulp. As a Japanese craft, it is registered as a UNESCO intangible cultural heritage.

Gampi tissue - Japanese tissue is a thin, strong paper made from vegetable fibres, in this case, from the gampi tree.

Shibori dyeing - Shibori is a Japanese manual resist dyeing technique, which produces patterns on fabric. Similar to tie-dying, shibori has been used since the 8thcentury. There are an unlimited number of ways one can bind, stitch, fold, twist, or compress cloth for shibori, and each way results in very different patterns. Each method is used to achieve a certain result, but each method is also used to work in harmony with the type of cloth used. Therefore, the technique used in shibori depends not only on the desired pattern, but the characteristics of the cloth being dyed. Also, different techniques can be used in conjunction with one another to achieve even more elaborate results.

Indigo Dye - Indigo is the legendary source of colourfast blues and its ability to produce a wide range of shades has made it the most successful dye plant ever known. Indigo grows all over the world but flourishes best in hot, sunny, humid areas. Indigo can give clear blues that range from the tint of a pale sky to a deep navy that is almost black. It is among the oldest dyes to be used for textile dyeing and printing. 

Encaustic - also known as hot wax painting, involves using heated beeswax to which coloured pigments are added. The liquid or paste is then applied to a surface—usually prepared wood, though canvas and other materials are often used. Because wax is used as the pigment binder, encaustics can be sculpted as well as painted. Other materials can be encased or collaged into the surface, or layered, using the encaustic medium to stick them to the surface.

Intaglio -  the 'family' of printing and printmaking techniques in which the image is incised into a surface and the incised line or sunken area holds the ink. It is the direct opposite of a relief print. Intaglio processes would include etching, drypoint, and engraving.

Collograph is a relief-printing process, generally involving attaching shapes, fibers, texture mediums, etc., to a piece of wood or cardboard.

Drypoint - a printmaking technique of the intaglio family, in which an image is incised into a bare copper plate with a hard-pointed "needle" of sharp metal or diamond point. In principle, the method is practically identical to engraving. It is different from etching in that no acid is used.

Lithography - a printing process that uses a flat stone or metal plate on which the image areas are 'drawn' using a greasy substance. Ink will adhere to the greasy areas, while the non-image areas are made ink-repellent. From this, a print is made.