Functional ware is considered objects like bowls or mugs that will be holding foods or liquids. There are a wide variety of different types of clays ranging from dark stoneware to smooth white porcelain or slightly grogged textured clays that are suitable as long as they have a low water absorption rate. For stoneware clays look for a claybody with less than 3% absorbtion and for porcelain look for less than 1%.
Recommended clays for Cone 10: Miller/Laguna Clays BMix10, 750, 900. Standard Clays: 153, 259, 306, 181, 182. For Cone 5-6: Miller/Laguna Clays Bmix5, 40, 45, 50, 55, 60, 65. Standard Clays: 112, 240, 266, 553, 563, 153, 259, 306, 181, 182.
Many stoneware clays will work well for ovenware, but clays that can handle the thermal shock of low to high temperatures work best. Cone 5 stonewares tend to be less susceptible to thermal shock but all ovenware made of stoneware should be heated and cooled gradually. Selecting a glaze that fits well and can also withstand the heating and cooling changes is necessary and may take some testing to figure out what works best.
Recommended clays for Cone 10 include: Miller/Laguna 750, 900. Standard Clays: 153, 259. Cone 5-6: Miller/Laguna Clays 60, 70, 45. Standard Clays 112, 153, 259.
Floor & Outdoor Tile
Tiles should be made from a strong, durable clay to withstand wear and tear and changes in temperature. Commercial producers employ special production techniques to increase the durability and provide lower shrinkage. You'll want to select a tile with grog for floor tiles and clays with low absorption rates (2% or less) for outdoor tiles. Glazing outdoor tiles and using a cover sealant will help protect your tiles from the thermal shock of changing weather.
Recommended clays for floor tile include Cone 10: Miller/Laguna Clays 900, 900. Standard Clays 108. Cone 5-6: Laguna/Miller 45, 60. Standard Clays 108, 420, 547. Low Fire Cone 06-04: Laguna/ Miller Clays 26, Standard Clays 104. For outdoor tiles use 900, 80, 90, 65, 66 547, or 26.
Sculpture claybodies contain significant amounts of sand and grog in various mesh sizes and are formulated for a low rate of shrinkage. These clays are designed to accommodate large handbuilt, wheel thrown or sculpted projects. Recommended clays for Cone 10 include: Miller/Laguna 950, 900. Standard Clays 108. Cone 5-6: Miller/Laguna Clays 45, 66, 75. Standard Clays: 547, 420, 239. Low Fire Cone 06-04: Miller/Laguna 10G, 20G, 26, Standard Clays 104, 105G, 239.
Atmospheric clays including raku, woodfire, salt fire, and reduction must be durable to withstand the thermal shock or changing temperatures. They should also have good flashing properties if used for woodfiring, salt firing, or reduction. Recommended clays for Cone 10 include: Miller/Laguna Bmix10. Standard Clays: 437, 621, 508, 119, 153, 507. Highwater Clays: Helios, Loafers Glory, Craggy Crunch, Phoenix. For raku use Miller/Laguna 200, 250, or Standard Clay 239