Specialist Crafts Terracotta Earthenware Grogged Clay - 12.5kg

Specialist Crafts Terracotta Earthenware Grogged Clay is a traditional terracotta clay containing 10% grog, providing additional structural strength and stability for hand-building and sculptural ceramics. Grog is pre-fired, crushed ceramic material added to clay to help support its structure during construction and drying.

Particularly suited to hand-building techniques, this grogged earthenware clay is useful for coil building, slab construction and creating larger ceramic forms. The added grog provides a more textured working consistency than smooth terracotta clay, helping support shapes as they are built.

The clay's natural iron oxide content produces warm, earthy colours when kiln fired. Firing towards the lower end of the recommended range develops traditional terracotta tones, while higher temperatures produce a darker brown clay body. This allows students to explore how firing temperature influences the appearance of ceramic materials.

With a shrinkage rate of approximately 9%, the clay is suitable for projects where structural control and dimensional planning are important. Supplied in a 12.5kg bag for school, college and specialist ceramics studios.

Key Features

Terracotta earthenware clay containing 10% grog

Added structural strength for hand-building

Suitable for coil building, slab work and sculpture

Textured clay body

Iron oxide content produces traditional terracotta colours

Higher firing temperatures develop a browner finish

Shrinkage rate: approximately 9%

Bisque firing range: 1000–1040°C

Glaze firing range: 1040–1160°C

Supplied in a 12.5kg bag

Firing Temperatures

Bisque firing: 1000–1040°C

Glaze firing: 1040–1160°C

Grog Content: 10%

Shrinkage Rate: Approximately 9%

Best For

Hand-building and sculptural ceramics

Coil building and slab construction

Larger ceramic forms

Exploring textured clay bodies

Traditional terracotta pottery

Investigating firing temperatures and clay colour

GCSE, A Level, FE and HE ceramics

School and college pottery studios

Important Information

Staining: Terracotta contains iron oxides that can stain clothing and work surfaces. Protect clothing, tables and surrounding areas during use.

Firing colour: Fire towards the lower end of the recommended temperature range for traditional terracotta colours. Higher temperatures produce a browner clay body.

Drying and firing: Allow clay work to dry slowly and thoroughly before kiln firing. Use compatible earthenware glazes within the recommended firing range.

Water resistance: Kiln-fired earthenware is not automatically waterproof. For pottery intended to hold liquids or be exposed to frost, apply a suitable glaze to reduce water absorption, ensuring the glaze is free from pinholes and crazing. Glazing does not guarantee complete impermeability or frost resistance.

Protecting surfaces: Always place vessels holding water on a protective mat to help prevent moisture damage to porous surfaces such as wood.