The Journal of Australian Ceramics Vol 49 No 1 April 2010

Technical: Lustre
Dodo Lustre Plate, 2009, sIlver and copper lustre on a copper and cobalt ground with clear glaze over, diam.3Ocm
photo; Kerry Bosworth
Here is the method I use:
We throw with porcelain because we are familiar with it. We then spray the dry pot with various oxides
to give a base colour before biscuiting to 126S 0 C (Orton cone 9). The pots are then dipped in clear
'earthenware' glaze, which has to be thick enough to adhere. It helps if the pot is warm and the glaze
is thickened with a little calcium chloride. Weigh the glaze first (adding water makes it lighter), because
th ickness is critical - too thick and it crazes, too thin and it is unpleasant to touch. After fettling, we re-fire
to cone as.
Now the brush decoration - I add water to my lustre pigments, which are left like caked mud in labelled
saucers from the last decorating session. I assemble great numbers of brushes, a generous container of
water for washing brushes at the end of each day's work, a box of large tissues and plenty of cotton buds.
Also handy is some gum arabic, a variety of round and chisel-ended bits of wood and some fine glass paper
to keep their profiles true. Bamboo is good because it doesn't wear too easily.
The thickness of the clay paste is important. Generally speaking, it should be applied thinner than you
might think - like single cream . Gum helps pigments, which contain a lot of clay, to flow. A few drops
render a glutinous clay paste brushable. Painting on a glazed surface with mud may seem an impossible
task at first, but it comes with practice. Handle the pots as little as possible before decorating. Clay paste
is water-based, and fingerprints on the pot can repel a design when you are half way to finishing it. It is
THE JOURNAL OF AUSTRALIAN CERAMICS APRIL 2010 77