Burnishing A Pot

Burnishing clay is a technique that gives pottery a smooth sheen without using a ceramic glaze. It involves rubbing the clay with a hard object, like a smooth pebble or the back of a spoon. Note, the pottery you are burnishing will only become as smooth as the object you are using. Any nicks or uneven bumps in the burnishing object will damage the clay surface. The action compresses the surface particles of clay, aligning the clay platelets. This creates the reflective surface.

Burnishing is an ancient tradition and evolved before glazes had been developed. Whilst burnishing does create a moisture repellent surface, especially if waxed, it is not watertight. As such, burnished pottery is largely decorative and can’t be used as functional ware.

Burnished pottery needs to be fired below 1000°C otherwise it loses its polish. It is often used as a way of preparing pottery for pit firing, saggar firing, or raku. All of which involve firing at lower temperatures.   

Clay can be burnished when it is leather hard by holding it in your lap or on a cushion. There is no right or wrong way of rubbing the clay. It’s important however to change the direction of your stroke because if you continue rubbing in one direction you can get lines and ridges in the clay. 

It’s also possible to burnish pottery on the wheel. After trimming, grab your burnishing stone or metal spoon and hold it against the pot as it rotates. 

You can also burnish bone dry clay however you need to add some source of moisture. To do this is, add a little water or oil, or a mixture of both, with a sponge. The lubricant will be absorbed quickly into the bone dry surface. So add a little at a time with the sponge and burnish that area before moving onto the next.

story from the pottery wheel