Which dust is best? Great question! Here's a breakdown:
Fondust: Designed for coloring food with very low water content. Use it for fondant, sugar work, royal icing, buttercream, cake mix, candy, etc. Practically everything except pure chocolate.
Petal Dust: Water soluble, designed for dry application using a brush. It can also be used to color most other food products. Has a matte finish.
Hybrid Lustre Dust: Can be brushed on dry or with water, alcohol or lemon extract. Has a luster finish (somewhere between metallic and matte)