I use NZ-6 mid-range porcelain clay (cone 4-6) from New Zealand. Porcelain involves years of experience to mold and fire successfully as it is extremely persnickety. Cracks, warping and slumping are commonplace. Because each of my sculptures are unique, they have to be hand modeled. No molds are ever used. After creating a sketch of my planed work, I sculpt the entire piece, then I cut the sculpture into logical pieces and wrap them in plastic. I hollow the sections out to prevent cracking and air pockets. Then I reassemble all the pieces and refine the details. I wrap the smaller, more delicate parts with plastic and wait until everything is completely and evenly dried. This is where 50% of cracks could occur. This process can take three to four weeks depending on humidity levels and the complexity of the work. Once the clay is completely dry (the greenware state) I place the fragile sculpture into the kiln. The firing is a tricky time because the kiln has to increase temperature very slowly with many 'ramp and hold' settings, eventually reaching approximately 2100 degrees Fahrenheit. This firing takes 32 hours to complete. The temperature is brought down at an equally slow pace. After cooling, I can apply a clear glaze and fire again to cone 5 (2118 degrees). The whole firing process takes over 60 hours!