Lumiere Lusters™ by JetAge S

Productstudio are specialty color shifting, heat resistant metal oxide powders and flakes that work glittery magic in powder coating, and a multitude of other mediums including enamel. These flakes are rated to resist heat up to about 1400F, and don’t have a specific coefficient. Similar to Dichroic Extract powder, they throw off a lot of color-shifting sparkle depending on the angle viewed. The larger particle sizes create a lot of shine that you cannot get from micas, and give quite a different effect from powdered extract. They’re also a great cost effective alternative to dichroic coatings and are more heat tolerant than regular powdered micas.

For use with powder coating it is best to cover the coating with a transparent powder coating.   

Note:  For use with enamel it is recommended to use a low fire flux over top and to use on items that are not for personal wear as the lusters may flake off.   I have created jewellery with these lusters, but it is a slow process to ensure the flakes are covered using 1400F or less to put a transparent layer overtop.   However, these are great for enamelled ornaments and art work and do not require a clear flux over top if not for wearing.

Small holds about .25 actual gram weight.

From "The Art of Fine Enamelling"

Jet Age Studio

Jet Age Studio makes a variety of flakes and powders that provide shimmering color to your enamels. They reflect like dichroic glass but are different. They sell a sample pack of each color/type for about $2.00 plus shipping. This is a good way to test what you'll eventually want to use most of. Note: I find their naming of products confusing - be aware of this but try whichever color you like with a sample. Like Lusters, only the actual product that touches the enamel will fire on. That is, if you have a double layer, the 2nd layer will wipe off after the piece cools.

A good one to start with is their flake product Lumiere Lusters, which I have used and love. I apply them with just brushing my enamel surface with Klyr-Fire and using the brush to bring the LL from the jar to the area I want to apply them. If the flakes are too big, I break them up with sharp tweezers and move them around with the brush or tweezers. I fire at 1450°F for about 1 min 15 sec, which is also true for the others noted below. Note: I have only tried these on unleaded enamel but can't see why lead bearing couldn't be used.