Decorating pots with a brush is something that frightens many potters. Perhaps, having spent time and energy making a pot they are afraid to spoil it with designs or decorations they are uncertain of, or perhaps they simply have no confidence in their ability to use a brush.
Whatever the reason, proficiency only comes with practice and if you want to decorate in this way, you have to take that risk. Study pieces you admire, visit the V & A or other collections, the road to improvement is not mysterious, but it does involve commitment and perseverance.
The particular technique I use is called reduction fired lustre, or clay paste lustre. First used a thousand years ago in the Middle East, lustre pottery entered Spain with the Moors, and was adopted in a couple of centres in 17th Century Italy. But it only appeared in Britain in the 19th century through the genius of William De Morgan, a friend of William Morris. It involves painting on the glazed pot with a mixture of clay and finely ground silver or copper salts, and refiring in an atmosphere starved of oxygen.
As far as brush decoration goes, this technique has the advantage that anything you do not like can be wiped away easily because you are painting on the glazed surface of the pot. Until it is fired, a sponge and water is all you need to remove the paste. The challenge and the joy, lie in refiring the piece.
Success or failure is balanced on a knife edge; but when the firing is good, the hard work and the worry is forgotten and light reflected off silver and copper deposited in the glaze gives a new dimension to the work, sometimes accompanied by iridescence in the glaze or flashing of the pigment- all gifts from the fire for which we can only be thankful.
You don’t need a great many brushes or brush strokes, to begin this work and with practice you will learn what you can do with each brush. I hate throwing old brushes away and have acquired a collection. Sometimes, I buy a brush simply for the delight of having a beautiful new implement in my hand. As one craftsman to another, I salute Rosemary!