Zero4 fritware is more resistant to overfiring than you might think
Most technical sources would say that one of the disadvantages of fritware bodies is volatility in firing. They should deform and warp more readily as they reach maturity. And if overfired we would expect rapid increase in deformation. However, that is not the experience we have had with Zero4low fireporcelain. It reaches zero porosity (maximum density by cone 06, 1800F). Yet it is still very stable at cone 04 which is more than 100F hotter. Also, at cone 04 it achieves very good translucency. But this cast piece, which is about 10 cm tall (4 in) has a wall thickness of only 2.5mm, has wide flat areas that have not warped and it is fired another 100F hotter (cone 02). Yet it is not warping! This body has the same density and firing shrinkage across the entire cone 06-02 range.