I use both slip and plastic clay.
I have used a wide variety of slip recipes over the years and continue to utilize both commercial slip and slip mixed from recipes in the studio. All are fired to cone ten and can be characterized as stoneware or ‘porcelaneous stoneware’.
My primary plastic throwing body is a variation on a Val Cushing stoneware recipe that substitutes Lincoln Fire Clay for some of the Hawthorn Bond. It is formulated primarily to provide flashing in atmospheric firing conditions, but works well in straight reduction. In straight gas reduction it is a pleasant light grey. Fired in heavy atmospheric conditions it varies widely from light grey to dark brown to bright orange. It is a good throwing body with some added tooth from the large particles found in the Lincoln, but smooth enough that it works well with press molds. Lincoln fire clay, mined in central California, is used in commercially produced, salt-glazed sewer pipe.
I live and work at Watershed Center for the Ceramic Arts, a residency facility located in Mid-Coast Maine. One of the many benefits of residing at a ceramic residency facility is the availability of a wide variety of a materials. Watershed is blessed with a deposit of locally mined alluvial terracotta left over from its days as a brick factory. It is a coarse clay with many impurities, but fires to a beautiful red in oxidation at cone 04, going to toastier browns up to its vitrification point at cone 1. At high temperatures it produces a satisfying greenish glaze. I am currently developing a series of garden planters using the Watershed terracotta.
Often, residents will leave behind clay or Watershed will receive a donation of clay and I’m not above using commercial plastic bodies and have had good results with Highwater Clay’s cone 10 stoneware, “Wonder White”. I’m not a fan of Laguna’s “B-mix”, though some of my first jugs were cone 6 B-mix fired to cone ten with satisfactory results.