Naked raku is a technique wherein you don’t cover your pots with glaze, you cover them with a slip that, when applied to a bisqued pot in a thick enough layer, will begin to crack even before the pot goes into the second firing. If you can manage to get the slip to crack without completely falling off the pot while you heat it in the raku kiln and then plunge it into a bucket filled with shredded paper, the solid slip areas will protect the clay so it maintains its original colour, while the cracks allow the smoke through so that the clay turns black along the cracks.
In the best case scenario, when the pots have cooled the slip falls off with only a little help from you and your fettling knife, so that you are left with a lovely crackle pattern on the smoothly burnished surface. (Burnished pots work best for this technique.)
In the worst case scenario, when the pots have cooled the slip is still stuck to the pot and only comes off after many hours of chipping and scraping that not only drains your soul but also leave the smoothly burnished surface scratched and knicked. Before it gets to this point the best thing to do is to fling the pot into the garbage (or against the wall to the accompaniment of Handel’s Messiah) and start all over again—something that I have done many times.
The problem is that I don’t raku often enough to get good at it, but recently I was able to participate in two consecutive raku firings that were only a few weeks apart, and I made some headway. The first firing was a disaster: I fired five slip-covered pots, none of which shed their slip easily and four of which went into the garbage. For the second firing I applied the slip much more thickly and unevenly and I was rewarded with two pots that were easy to de-slip. A half-hour or so of gently nudging the slip off, some scrubbing with a soap pad, an application of conservator’s wax, and I had two lovely, crackly pots.
My two successes have intricate patterns of black and grey crackle but like most potters, I’m never satisfied: now I want fewer cracks and more bright white areas, which is what I love about this business—there’s always something else to try.
“Of making many pots there is no end”—with apologies to Ecclesiastes 12:12.