Posted 14 April 2013 - 06:20 PM
The quality of the brushing medium matters to get the fluid gestural qualities of line you are observing.
It is likely not just oxide and water being used. Plus the cobalt (and manganese) likely has been ground (by hand) very finely.
Decorating mediums used for this kind of decoration often contain multiple ingredients........ the coloring oxide, a small amount of a flux supplier like a frit, a small amount of a very fine clay (like a ball clay), then suspended in a cariier that is a mixture of a suryp made by boiling seaweed til it disolves, or something like propylene glycol, glycerine, and often also a glue to make it not smudge..... like a rice flour glue or even something like Elmers white glue.
It is important to GRIND the mixture very finely. This is done in a porcelain mortar and pestle by hand, or in a grinding machine that automates this process.
Use red food coloring to rough out the design on the piece...... and then follow up with the actual painting medium. Red food coloring burns out.
Professor of Ceramics; New Hampshire Insitute of Art
Guest Professor, Wuxi Institute of Arts and Science, Yixing, China
Former President and Past President; Potters Council