as long as you buy quality clay your fine. Even quality clay is...... dirt cheap. Example for those that don't live some place that has clay available local. https://www.amazon.com/AMACO-46318R-Clay-25-Pound-White/dp/B0009RLJZ4/ref=sr_1_10?ie=UTF8&qid=1472236862&sr=8-10&keywords=porcelain+clay