More Mochaware Pictures!

Mochaware, also known as mocha diffusion, is a difficult technique mastered by very few pottery artists, but the result is beautiful dendrite patterns resembling tree branches, neurons in the brain, and moss agate - mineral deposits of manganese and iron trapped in rock furrows.

First invented in Staffordshire (UK) in the 1780's during the Industrial Revolution, mochaware was mass-produced for the working class people. Although machinery at the time was considered sophisticated, Mochaware technique required a certain amount of human intervention, which thereby increased irregularities in the pieces (e.g. fingerprints and smudges).

Mochaware decoration is achieved by an acid-base reaction and surface tension. Leatherhard pots are dipped into a wet slip (runny clay and water), and a tobacco-based mixture (called "tea") containing tobacco juice and colorant is lightly touched to the slip with a well-loaded brush of tea.

My formulas for slip, tea, and glaze have been optimized with redware clay. Slip viscosity, oxide strength, and glaze recipe are important parameters that need to be optimized.

This mochaware project has been lingering in my studio for about 1 year, and finally I feel comfortable publishing the pictures. I have saved a lot of my first pots in the process, and plan to post them at a different blog address: http://mochaware.blogspot.com/. This will enable me to delineate my stoneware clay projects from my mochaware project. Please check both blog sites often, I update often - so hit reload constantly.

I will not comment on every picture below, but I thought one description would apply to most. The following picture is of a Mochaware vase with dendritic patterns in the middle and prominent banding above and below. The slip I use here is white, and I use a transparent glaze over the top and apply it to the whole pot including the handle. Note: Adding handles without slip or adhesive is very difficult and requires careful moisture control so a tight junction is made that'll survive firing.