Glazing and Firing
For a good finished piece, proper firing is essential. Maiolica is a type of low fire ceramics. The first firing of a low fire ceramics vessel should be hotter than the glaze firing. I bisque fire my greenware to Cone 04. Cone 04 in my electric kiln corresponds to a Fahrenheit temperature of 1949 degrees. An improper first firing can result in blisters appearing on the surface of the ceramic vessel in the second firing.
Part of the magic of maiolica is that the white glaze acts as a stable surface for decoration. The colors of the decorations sink into the white glaze during firing. I use a commercially made white glaze made by Hobby Colorobbia applied with a fan shaped brush. Thick glazing can cause painted decorations to run
I usually apply a thin coat of clear on top of the painted decoration prior to firing. This gives the final piece a nice finish. The top coat should be a very thin layer in order to avoid problems caused by having too much glaze.
There are a number of commercially made white glazes that will work for maiolica. Another maiolica artist, Julia Passamonti-Colamartino, has the following recommendations as an alternative to the Hobby Colorobbia Arctic White --
- Laguna EM 1002 -- Alabaster, which is a warm white
- Laguna EM 1146 -- Cool White (almost identical to Colorobbia Maiolica White)
- Laguna 1100 --
Eggshell, for a more "antique" look.
The Laguna glazes are available in gallon sizes and in
Fire the finished piece resting on kiln stilts. Fire in an electric kiln to cone 06 (Fahrenheit 1828 degrees) using a 15 to 20 minute
hold on the final temperature. The hold helps prevent small bumps in the finished surface.
There are a number of technical issues that can influence the finished product. On a hand thrown pottery piece, pinholing can be reduced by wet sponging a piece as the final step of trimming. Small pimples can occur with some colors, especially orange, if the underglaze is applied too thickly.
The best source I have found for trouble shooting technical problems is the appendix of a book -- The New Maiolica: Contemporary Approaches to Colour and Technique, University of Pennsylvania Press, 1999,
hardbound, 160 pages.