Professional Clay PF 550 Svend Bayer 100 KgProfessional Clay PF 550 Svend Bayer Available in 25 Kgs bags. Minimum order 100 Kgs. This clay has been extensively designed with Svend Bayer for wood firing and in particular prolonged wood firing. Low iron clays are used to give a vast colour range, corderite grog is added to give the clay a slightly grogged feel. Cone 12 can be reached over a long prolonged firing and is suitable for thrown and hand built pots. CATEGORY: Professional METHOD: