Snap, Crackle and Pop

...titanium dioxide...zinc oxide...cobalt oxide...red iron oxide...copper carbonate...

A more direct hands-on approach, with a different ceramics production process: Raku. The term Raku - literally, "enjoyment" or "ease" - derives from Jurakudai, the name of a palace in Kyoto in the 1500's.

A few years ago I attended an incredibly energetic workshop run by potter John Chipperfield in Suffolk. I got back into playing with mud again! We all made various pieces, either on the wheel, or hand-built, which he then biscuit-fired. We returned a few weekends later for the glazing and Big Outdoor Firing, in a kiln in his garden, brought to a roaring temperature of about 1,800 degrees F.

...some unglazed, sooty black areas around the base...

After a set time, and when the pieces are glowing red hot, they were drawn from the kiln with long iron tongs and plunged, smoking, into a trough full sawdust. This cooled the work down very quickly, causing the typical Raku look - fine, black, spidery-web crackle, a very desirable effect. This powerful process also uses the immediacy of the fire, smoke and dramatically fast reduction, to create an unpredictable texture on the pottery.

The unglazed areas have nowhere to get the oxygen from, so they take it from clay. Such a reducing atmosphere will turn clay grey-black, staining the exposed body surface with carbon, producing the powerful matt-black, smoked surface.

...and on the patterned areas inside....

The tense excitement as the final results emerge when the pots have cooled and been cleaned, proved irresistible, especially for the potters with pyromaniac tendencies.

You can see a combination of these
techniques, glazed and unglazed areas, on this bowl, where I cut various shapes from wide masking tape and arranged them on the bisque fired piece before spraying with white, speckled blue/grey - and coppery glazes.

....and some Copper Fuming visible on the inside too...

This Copper Fuming is achieved by using a mix of a 90% copper oxide and 10% glaze mixture, which gives an iridescent lustre - (sometimes) - creating a beautifully vibrant sheen. This bright, shining, metallic glaze is notoriously difficult to control and can apparently fade over time.