Apparently people would like to know how I make terra sigillata. My method, thanks to long-time Ceramics technician at Emily Carr U, Gail Carney, is low-tech and doesn’t involve chemical wizardry, just scales, a measuring jug and two very large buckets. I have a feeling some of the terra sig experts might find my method too unscientific but it produces what I want. Below is copied from my recipe hand-out for workshops.

To contrast with the very shiny glazed areas I like to use terra sigillata on some parts. I paint it onto bone-dry work, especially underneath.

Redart Terra Sigillata

Redart Clay powder                        2 kg

Water                                                8 litres

Calgon water softener                        3gm

 

Dissolve calgon in a little warm water, mix with the clay and water, sieve and leave for an hour. Then pour into another bucket every twenty minutes, discarding the bottom sludge, until there is almost no residue. The next day is too late to continue. The watery result can be left to evaporate or put in a large pot on the stove to bubble away the excess water.  Stir and apply with a brush to bone-dry ware in several thin layers. Pots can be dipped in terra sig or sprayed. It should still be fairly thin, like 1 percent milk. For a nice shine buff with a ball of scrunched-up thin plastic right after application. If the terra sig is too thick, like a slip, it may spall off.

Goldart Terra Sigillata

Goldart Clay powder                        500gm

Water                                                1 litre

Calgon                                                3gm

Good off-white and a basis for other colours, usually stains.