The Art of Burnishing
Before glazes were invented, potters discovered that rubbing a smooth stone across damp clay aligned surface particles, creating a reflective sheen. This technique has been practiced on every continent for thousands of years. African, Native American, Japanese, and Greek potters all developed sophisticated burnishing traditions.
Stephen Jepson taught burnishing at UCF as both a practical technique and a connection to pottery's deepest roots. He considers it one of the most meditative processes — the slow, rhythmic polishing requires patience and presence.
Burnishing Methods
Stone Burnishing
Use a smooth, rounded stone — river rocks or tumbled semi-precious stones — to rub the surface of leather-hard clay. Press firmly in overlapping circular motions. The pressure compresses surface particles so they reflect light. Work the entire surface systematically. Multiple passes produce higher sheen.
Spoon Burnishing
The back of a metal or plastic spoon works as a burnishing tool. The curved surface contacts a wide area, making it faster than stone burnishing. A stainless steel spoon produces more pressure and higher sheen. Everyone has a spoon.
Terra Sigillata
A refined clay slip that fires to a soft sheen. Mix clay with water and a deflocculant, let settle, and decant the finest particles. Apply thin layers to bone-dry ware and polish with a soft cloth. Fire to low temperature — cone 06 to cone 04 — to preserve the sheen.
Leather Burnishing
Rub the surface with soft leather — chamois or suede. Gentler than stone, producing a softer sheen. Excellent for final smoothing after stone burnishing. The leather conforms to curved surfaces and reaches recessed areas.
Keys to Successful Burnishing
Timing
The clay must be at exactly the right moisture — late leather-hard. Not tacky but still responding to pressure. Test by pressing your thumbnail — it should leave a shallow impression without clay sticking.
Clay Selection
Fine-grained, smooth clay burnishes best. Porcelain produces the highest sheen. Smooth stoneware without grog is also excellent. Grogged clay cannot be burnished to a high sheen.
Firing Temperature
Burnished surfaces are destroyed by high firing temperatures. Fire to cone 06 through cone 04 to preserve the polish. Pit firing, saggar firing, and raku are compatible with burnished surfaces. A cone 6 firing will destroy the sheen.
Burnishing and Alternative Firing
Burnished pottery is a natural partner for pit firing and saggar firing. The polished surface catches smoke, flame flashes, and mineral deposits beautifully. Carbon penetrates the surface, creating dramatic patterns. The combination produces some of the most dramatic surfaces in all of ceramics.
Learn from Stephen Jepson
Stephen's pottery video lessons cover burnishing, terra sigillata, and surface treatment techniques. One-time purchase, lifetime access.