|Someone did once say I looked like a bear, but at least I am smiling! (Photo by Rhonda.)|
As usual I have several projects on the go and it is probably easier to give you an overview of them by listing the most recent one out of the kiln, and going back from there. Thinking about it further, I realize I had better do this edition in two parts otherwise it will be toooooo loooong!
|Yes, well... a rooster. I made a lino cut, pressed it into wet clay. When ready for glaze firing I painted the rooster green with some copper carbonate, and the other colours were some manganese dioxide and red iron oxide.|
I say "Majolica", you say "Maiolica"..
Last week I took a smallish batch of earthenware mugs, two single person earthenware casseroles, and a couple of dishes from the kiln. I enjoyed making these and playing with some majolica decoration - something I haven't done for years.
Some of you who may be reading this are very accomplished at Majolica decoration and have perfected it to a high degree, my own adventures thus far have been very basic, but quite enjoyable.
Majolica is also known as "maiolica", which is probably more correct, and also appears as Talavera in Mexico. The "real thing" was earthenware that had a lead glaze that had been opacified with tin oxide. The decoration was painted onto the unfired glaze with metal oxides, and the firing fused glaze and decoration together.
Majolica these days is more likely to have a borax frit based glaze that has been opacified with zirconium oxide. This practical non toxic glaze will probably lack the "warmth" of the traditional glazes. Modern ceramicists are also quite likely to use glaze stains that are prepared in nearly every colour of the visible spectrum, rather than metal oxides.
For this experiment, I used a commercial white glaze (because I happened to have some), and metal oxides. The metal oxides were prepared according to an article I read by Linda Arbuckle, whose work I have admired for years. I found the article here http://lindaarbuckle.com/handouts/majolica-handout.pdf
I used copper carbonate, for green
red iron oxide, reddish brown
cobalt carbonate, blue
and chromium oxide, for a stronger mid green
(well, I hoped for these colours... but got rather different results!!)
To one teaspoon each of these I added one teaspoon bentonite and one teaspoon frit 4124 (a medium soft borax frit, you may have 3124 or similar).
I also used manganese dioxide, and to one teaspoon of this I added one teaspoon of bentonite and one teaspoon of frit 4110. This frit should help manganese develop a purple brown.
I stirred each of the oxide/bentonite/frit dry mixtures together in small ceramic bowls until well blended, then progressively added water (whilst stirring) to make each mixture a creamy brushable liquid.
I made up about a litre of commercial white glaze with about 1 percent red iron oxide to warm up the "refrigerator white" and a couple of percent of bentonite to help the glaze suspend in the glaze bucket and to give it a less powdery surface when dry and unfired. I glazed the pots by pouring and/or dipping them in the commercial white glaze, then decorated the glaze when it was dry. In spite of the bentonite, the glaze was rather powdery, and really needed something more to harden its surface. If I were to use this particular glaze again I would look at adding a gum such as CMC (carboxymethylcellulose) to bind the glaze together.
In spite of the powdery nature of the glaze, I managed to decorate without too many problems, although the chromium oxide tended to pull off the glaze when dry, I may have applied this a little too thickly.
I enjoyed just letting the brush dance along the surface, and improvising simple blobby patterns.
The work looked like this before firing...
Rather different afterwards.
Green: copper carbonate was an OK copper green but did not "sing".
Blue: cobalt was grayer and more subdued than expected.
Purple brown: manganese was more of a pale mid brown rather than purple brown.
Red brown: red iron oxide gave dark charcoal brown.
Mid green: chromium oxide gave brown rather than green.
|cobalt carbonate for blue and chromium oxide giving brown thin lines|
|mid brown manganese dioxide "blobs, dark red iron oxide lines, and copper carbonate green "blobs"|
None of the above were "wrong" or "faults" as such, but just showed what particular oxides will look like when put over this commercial glaze. If I were to continue using this glaze in future, I would have to learn to work within its limitations, this is the case for any glaze. Every one has a different personality. One problem with using commercial glazes (this one was Abbot's White), is that the manufacturers can be cagey about releasing information about what ingredients have been used to make the glaze, it is difficult then to know how they will affect metal oxides or other glaze materials. You just have to test and see what happens!
Anyway, I enjoyed this little majolica excursion, and will do more. I will make up some other white glaze bases for my next test.
|A single person casserole|
|That rooster dish|
To my delight, as I write this, I have also discovered a blog that Linda Arbuckle kept between 2012 and 2014, it seems a wonderful resource of information for anyone that is interested in decorating ceramics http://lindaarbuckle.com/lindaarbuckle-blog/. Thank you Linda!