Majolica Glaze
As I mentioned in the first post in this Incubator Project series, one of the things that excites me about the work of Frances Richards is her use of majolica decoration. Majolica decoration (I’m informed by The Potter’s Dictionary of Materials and Techniques by Frank and Janet Hamer) originated in the Mediterranean where the drier climate meant these low fired porous vessels would still be practical. Earthenware was traditionally fired to a very low bisque then glazed in a tin-rich glaze to create an opaque white on top of which coloured oxides were then brushed.
Knowing nothing about Majolica prior to this, I was at first confused that the technique seems to have interchangeable names, was it maiolica or majolica? Luckily the national trust website was on hand to clarify with their article https://www.nationaltrust.org.uk/features/what-are-maiolica-and-majolica which suggests “This distinction (majolica for nineteenth-century lead-glazed and maiolica for Italian tin-glazed) is still generally accepted in Britain.” although it admits that there is still debate whether this is entirely correct. Rather than tin to add whiteness to my glaze, I discovered that Zircon (Zirconium Silicate) can have the same effect on opacity for half the price. Feeling too that it seemed rather sensible to avoid lead, I decided on a lead-free recipe.
Matthias Ostermann in his book ‘The New Majolica’ (1999) suggests three basic majolica glazes which work best for him. I decided to go with number 1, his standard glaze which is as follows:
1046C (Cone 5)
Ferro frit 3124 60
Ferro frit 3195 10
Ball Clay 6.5
China Clay 6.5
Quartz 4
Whiting 2
Zircopax 11
Having mainly worked with stoneware throughout my three years at university, I have very little knowledge of low firing glazes so this is a big learning curve for me. I adjusted the recipe a little because I only had the first frit 3124 at hand. The frits are almost glazes by themselves, the ball clay and kaolin help keep the glaze in suspension, whiting contributes to surface hardness and Zircon is the opacifier.
I made a second batch of glaze without the Zircon, a transparent base glaze. Adding one part oxide to three parts of this base glaze using a teaspoon I created a range of mixtures which will act as my colour palette. On the test tiles below you can see the results of the oxides on the majolica base glaze, from left to right:
Cobalt oxide, Red iron oxide, Chrome oxide, Antimony Oxide, Manganese Dioxide, Manganese over antimony, Cobalt over Red Iron Oxide.
Having read that antimony produces bright yellow I was surprised when it resulted in a foamy bright white. It turns out it only produces yellow when in combination with lead oxide (which my glaze doesn’t contain as the base is a leadless high calcium borosilicate frit). The cobalt and chrome produced very vibrant flat colours which I feel very happy with. The red iron oxide was a bit washed out (maybe the glaze mixture was too watered down and the same can be said for the manganese). I am aware though that in the early 20th century, Richards wouldn’t have had ready available stains so using oxides will get me closer to her colour palette. Her red overglaze is much more vibrant though than the red iron oxide I used so I plan to find a red stain and perhaps a black and yellow to complete my palette too.
One thing I am aware of with majolicas is that the base glaze needs to be applied thickly or it will look washed out. I have a terrible habit of messing up my glaze application. As you can see on the tiles, where they have been dipped once, the glaze is too thin. Higher up where there are 2-3 coats is much better. My next step will be to buy a big bucket into which I can make up enough litres of this glaze to dip my sculptures and ensure a good, even coverage.
