Shivering is a glaze fault where slivers of glaze flake away from a pot, usually at rims, edges and handles. It happens when the glaze shrinks much less than the clay on cooling and is squeezed until it pops off.
What Is Shivering?
Digitalfire describes shivering as the opposite of crazing. In crazing, the glaze is stretched and cracks; in shivering, it is under too much compression. Both come from a mismatch in thermal expansion between the glaze and the clay.
Shivering is much less common than crazing, because glazes usually expand more than clay bodies and tolerate being compressed much better than being stretched. It tends to show up with low-expansion glazes on high-expansion bodies, and is worst on sharp edges where stress concentrates.
It is a safety issue on tableware, because the flakes can be razor sharp and can come off into food or drink. Pieces that shiver should be retired from kitchen use.
The fix is the same process as for crazing in reverse: raise the glaze’s expansion, choose a different glaze, or use a clay that suits it. Rounding over rims before glazing reduces the stress at edges, and test tiles with a sharp edge show the problem early.
This pottery glossary entry from Le Studio Art Space is general educational content. Always follow the clay, glaze and kiln makers’ data for your own materials and equipment.