This is a stainless steel spoon that has been dipped into a ceramic engobe that has been flocculated using powdered epsom salts. Without the salts the slip completely runs off leaving only a film. But with the right amount it stays on the spoon in an even layer (as a gel), then hardens as it dewaters (left) and finally dries completely (right) with no cracks! It fired to cone 03 with no cracks. If this were fired high enough it would transform to a glaze. But it would craze. Special low expansion frits are available to make enamels for metals.
The flocculation process enables technicians in ceramics to create an engobe or glaze slurry that gels and goes on to the ware in a thick yet even layer that does not drip.