Supplies Gold in faceups

I don't think they'll cause problems. I've used Coliro watercolors and Skrim watercolors (both companies offer a vide variety of shimmery/colorshift aquarell pans) on face-ups and never had any kind of reaction with it and the sealant. I've also used Schminckes Reinbleichgold and Green Stuff Worlds pure metal pigments because I really love gold accents, and didn't have problems with them either. Make sure to seal the head well beforehand and you're good to go.

Just keep in mind that any kind of sealant will dull the shinyness a bit, but in most cases it's not really noticeable.

 

I've used the exact Gansai Tambi Starry set on a number of my faceups and they're fine No problems with MSC.

 

I use Folk Art Treasure Gold acrylic paints: it's kind of pricy for what it is but it's the only metallic acrylic I've ever used that actually looks decently opaque and isn't just glitter suspended in water.

 

If you're not sure if it might interact, you could test some of the methods on a headcap- then if it stains the resin even a little, no one will ever see it.