Final answer:
Maria and Julian Martinez created black-on-black ceramic vessels by smothering the fire with powdered manure during the firing process to produce a reducing atmosphere, giving the ceramics their distinctive, blackened appearance.
Step-by-step explanation:
The technique used by Maria Martinez and Julian Martinez to create black-on-black ceramic vessels is by smothering the fire with powdered manure during the firing process. This method creates a reducing atmosphere in the kiln, limiting the amount of oxygen and thereby allowing the entire piece to turn black. After partial cooling, oxygen is reintroduced, causing the untreated surfaces to return to a lighter color, while the smoked areas remain black. The technique requires precision and control to create the black-on-black effect, and it is a testament to the artistic skill and expertise of the Martinez duo.
This method of firing, which is similar to the ancient techniques used by Greek potters and others, adds remarkable character and beauty to ceramic art. The Martinez couple did not use a potter's wheel; instead, they formed their clay by hand and with the use of simple tools for their impressive vessels.