Dichroic Effects in Enamel — Turritella Designs

The last few weeks, I have been experimenting with some dichroic decals and powders that are more commonly used in glass fusing, and lampworking applications. Unfortunately, due to the incredible shine and reflective nature of dichroic coatings, good photographs of the sample pieces were very difficult to capture, but I tried my best.

Dichroic decal paper is a finicky mistress when paired with enamel. If the decals are fused at too high a temperature, the metallic oxides that give the dichroic sparkle can disappear in at least three different ways. The first disappearance can be caused by over-firing the uncoated decal and causing it to burn away to ash. Firing the enamel at a low temperature reduces the risk of this occurring. The second disappearance can be caused by over-firing a coat of enamel that has been applied over the decal to protect the dichroic surface. Unfortunately, in this case the metallic oxides that create the dichroic effect are likely absorbed into the glass and dissolve, leaving a cloudy residue behind. The third disappearance can be caused by continually firing a piece with an enamel-coated dichroic decal, even at a low temperature. Dichroic decals should be applied in the very last firings of the piece, because subsequent re-firings seem to start to dissolve the dichroic oxides, even at lower firing temperatures.

The second dichroic coating I have been experimenting with is dichroic extract. While this dichroic powder is significantly more expensive than the dichroic decal paper, it also seems to be quite a bit more durable. It can be tricky to apply accurately, so I have been using overglaze black enamel to add patterns and cleanly break up divisions between dichroic colours.

In general, the dichroic decals seem to have more directional variation in colour, whereas the dichroic extracts seem to be more even in tone. Dichroic decals also often shift their colours in the kiln, whereas the dichroic extract powders are much more predicable in their appearance. For instance, while magenta/green decal paper shifts to a teal blue colour, the emerald dichroic extract remains emerald.

I think both dichroic decals and powders could be used effectively in complex enamel designs like Cloisonné, as long as they are used at low temperature and added in the finishing stages of the piece. I’m looking forward to using them as accents. I’m dreaming of iridescent bird feathers.