Philippe prefers to use a low-fire (fires to cone 06), white earthenware (water-based) clay without grog. Clays are manufactured locally so one purchased in California will be different from one in New York. Ceramic supply shops are the best source for this type of clay. A few that Philippe has personally used and finds closest to the texture he prefers are:Miller #10Laguna EM100 (available in the Northeast). Laguna EM700 (available in the Southeast).Laguna EM210 (available in the West).Standard 105NTSmooth Sculpture (available from Clay Planet in California).Laguna has distributors both in the US and internationally. Look for them here: Laguna Clay Distributors