© 2009 Anja Penger-Onyett

I throw my pots on the potters wheel using a white stoneware clay, almost as white as porcelain. I want the glazes to come out with the colours I intend them to be, not greatly influenced by the clay body underneath!

I mix all my glazes myself, starting from raw materials. There are hundreds of books available about glazes (and according to my husband I own them all!).

In addition to reading those books I also love to try a lot of them! There are some things you might be able to predict from a glaze like coefficient of extension (that is how much a glaze expands during the firing and shrinks during cooling). If this coefficient is greater than the coefficient of the clay body the glaze shows crazing (see picture to the right).

Sorry about all this technical talk: that is where my scientific background comes through! I use a computer program (Insight by Digitalfire corporation) to calculate some of the parameters that a new glaze might exhibit. Still I can’t predict the colour, that is mostly down to the firing cycle (see next page).

I love celadon glazes, as well as tenmokus. Both of those contain iron as the colouring oxide, just in different amounts. One of my other favourite glazes is a fine copper-red. All these glazes require reduction atmosphere during the glaze firing (see technical :: firing)