|Monthly Tech-Tip |
The L3954F engobe is tuned to have the same degree of vitrification as this porcelain (P300). I made a pint of a brushing version of it by mixing a 500 gram batch with 75g of Laguna Gum Solution and 280g water (it does not require VeeGum because it already contains a high percentage of plastic clay). Mixing in a kitchen blender gets all the lumps out. It paints beautifully onto leather-hard ware in sufficient thickness that one coat covers (this enables presenting this normally white burning body as a black porcelain to match the glaze). I make my own labels for single-jar brushing glaze and underglaze tests. They clearly show the code number, we assign these in our insight-live account for the project. Subsequently, the piece was bisque fired, black-glazed and fired at cone 6. The band painted on the base, which I did as a fix-up for a few tiny white bare spots, demonstrates something unexpected about this homemade engobe: It paints well on a vitrified surface, dries there without cracking and even fires there without shrinking or flaking off.
Engobes are high-clay slurries that are applied to leather hard or dry ceramics and fire opaque. They are used for functional or decorative purposes.