Plainsman M340 with 11% added 48 mesh kyanite. The kyanite was added to improve the plastic strength to stand up when throwing large shapes. It has done this. Its grainy texture (in an otherwise smooth body) is only slightly noticeable while throwing, but it lifts better. The kyanite was simply wedged into the clay using a slice-and-wedge technique, the stiffness was affected only slightly. An added benefit will be a reduction in the thermal expansion (and thus thermal utility) of the fired clay (of course there is a chance that glazes will need to be adjusted to deal with crazing).