The 'liquid colour' group of pots in this selection from the Crafts Study Centre collection shows a number of ways in which British studio potters of the twentieth century have approached the building up and application of colour in liquid form. The 15 pots included in the selection are vessels of broadly conventional shape based on domestic functions: all are bowls, jugs or bottles made of different ceramic bodies (earthenware, stoneware and porcelain), and all but one were thrown on a potter's wheel. The one exception is the highly-patterned, painted pot by John Maltby (No.8) which is slab built.
In pottery, a coating of colour can be provided by glaze, containing one or more colour-bearing ingredients in suspension, or by liquid clays, called slips. Glaze ingredients seen in this collection of pots include metal oxides, pigments, salt and wood ash. They can all produce different effects and surfaces; for instance, Katharine Pleydell-Bouverie frequently used all-over, smooth ash glazes on globular forms, harmonizing two deep colours in a subtle way (No.11, vase) . Lucie Rie used many glaze types but favoured the juxtaposition of a dark brown, semi-matt manganese pigment on one surface of a stoneware bowl with a shiny white one, or some other contrasting glaze, on the opposing surface, or another area (No.13, oval bowl) . Her later work exploits daring, frothed and pitted glazes of which a vase is included here (No.15).
The modern potter most closely identified with the use of slips is Michael Cardew, who worked with them from the 1920s to the 1970s (No.3, plate) , (No.4, bowl) , (No.5, cider jar) Sam Haile, active only in the late 1930s and 1940s, also favoured slip decoration, producing linear designs in a spare, contemporary idiom (No.7, dish) . Michael Casson used free finger-combed glaze decoration, as found in traditional English slipwares, as an inspiration for his jugs in saltglazed stoneware, dating from the 1970s and 80s (No.6, jug) . Svend Bayer, a potter who specialises in throwing large garden pots, often uses ash/clay glazes to partially coat the upper surfaces of his vessels, so that when fired they produce organic runs, streaks and colour changes as suitable for setting in a natural environment (No.2) .
Apart from the effects of glazes and slips on the exterior, colour can also come from within the body of the pot if, for instance, stains and oxides are mixed with the clay prior to throwing. An example of this may be seen in the 'spiral' bowl by Lucie Rie (No.14) included here. Colour can also be added to a ceramic object during firing if, for example, salt is thrown into the kiln to melt and form a glaze. In addition, firing in a wood-burning kiln, and exploiting various kiln atmospheres (with or without oxygen), also has a marked effect on the range of colours which can be produced by clays, slips and glazes.