Copper Matt Raku

 Copper Matt Raku is probably the most difficult form of Raku firing.The glaze is nearly 100% Copper Oxide. There is only a small amount of glass frit added to bond the copper to the pot.The glazed bowl is heated to 1020 °C , removed from the kiln red hot and placed on a bed of sawdust.The copper oxide is reduced and then oxidised again. It is this incredibly thin layer of copper oxide that provides colour, it refracts light in a similar way to oil on water, using thin film interference to produce a similar spectrum of colours but in a fixed,permanent form. You can often see a flame pattern, from the burning sawdust, fixed into the colours on the pot. The dark smoky bacground from raku firing and the spectrum of colours, are reminiscent, to us, of the Northern lights in the night sky.