I used Pearl Ex and other mica based pigments (Nyx Eyeshadow) mixed with gum arabic and water just thin enough to spread in the palette wells. I let them dry overnight and the powder that didn’t quite make it into the wells (shown in the photo) wiped right out.  Time consuming and messy … but so wonderfully worth it.  I love finding new ways to use old supplies.
Mix colors to make more shimmery paints.