My first encounter with crystalline glazes was an article in the July 1995 edition of the New Scientist magazine. The article described a ceramic process that I hadn’t heard of. It sounded very difficult but the pictures of the amazing results obtained by Kate Malone and Derek Clarkson made me appreciate why potters would go to extreme lengths to get similar results. I was hooked.
Shortly after I as born, my mother, Joan Bideau and her friend Joyce Ross formed a pottery business partnership known as ‘Rosseau’ and so pottery has been part of my life for as long as I can remember. I’m told that I threw my first pot on the wheel at the age of three. Two articles from the local newspaper dating from the early 1970s have some interesting information about how ‘Rosseau‘ came about.
My early inclination was towards the sciences, particularly chemistr,y but as things turned out, the degree I took was in Engineering and I subsequently worked in the Gas Turbine industry throughout my twenties and thirties.
It was the New Scientist article that renewed my interest in pottery. The crystalline glazing process was irresistible, appealing to my interests in both pottery and chemistry. One of the potters best known for crystalline glazes at the time, Derek Clarkson, had taught my mother at Burnley College and, as he lived locally, a meeting was soon arranged. Derek’s enthusiasm was contagious and he generously shared some of his recipes and techniques with me.
Starting with one of Derek’s recipes, I was soon producing crystalline glazed pieces of my own. Within a short time, I had my first exhibition, Potfest in the Pens (or just Potfest as it was known back in 1997) – it was a great sucess.
Since then, I have become a full time potter and have developed my own unique range of crystalline glazes, most of them tracing an ancestry back to that first Derek Clarkson recipe.
This is one of my early pieces. It is made from Limoges Special Porcelain, the glaze is one of Derek Clarkson’s recipies. This glaze is called ‘B5’ in my records. Looking at them now, in 2022, I see that my most recent glaze is labelled ‘B8095’.
A number of pieces similar to this one have recently been sold at auction, each commanding a price many times what I originally sold it for.
For those starting out with crystalline glazes, here is the recipe that Derek gave me. By crystalline glaze standards it is reliable and an excellent starting point for experimentation.
B5 Crystalline glaze for cone 9, by Derek Clarkson. B5 - amounts by mass: Ferro 3110 frit 43.5 Zinc oxide 28.5 Silica 19.5 Titanium dioxide 7.5 Alumina hydrate 0.4 China clay 0.6 +Manganese dioxide 1.3 +Cobalt oxide 0.2 The molar proportions, in Seger unity form are: Na2O 0.206 Al2O3 0.042 SiO2 1.60 K2O 0.019 B2O3 0.032 TiO2 0.18 CaO 0.094 ZnO 0.680