I am making decorations for an 1yr. birthday and I mixed 1/2 fondant with 1/2 gumpaste to make a crown and cover letter blocks. The crown turned out fine but was very dull in color so I used super pearl luster dust with clear vanilla to paint on both the crown and blocks. It looked great with a pearlized shine. Unfortunately the crown will not dry and seems to be getting more gummy. I've painted dust on fondant using vanilla on cookies before and had no problem. I'm not use to gumpaste so is that the problem. I have to remake this crown(for the 3D teddy bear) and make a larger one for one of the cakes and the letter blocks for the baby's name on the other cake. Any suggestions? Would I be better with just fondant and how can I get a shiny pearl finish? I appreciate any suggestions.

plain gumpaste is stronger, dries harder and faster than fondant or 50/50.

I was hoping against hope that the 50/50 fondant gumpaste crown would dry and reharden but it caved in. I don't know why using luster dust with vanilla would cause a hardened piece to gum up and collapse. Any clues before I try again?

Like JoAnnB said, "plain gumpaste is stronger, dries harder and faster than fondant or 50/50", so you have to let it stand plain and unpainted to dry for a longer time--if it's humid, perhaps a week or more.

Painting an item before it's completely dry actually holds in the moisture (sort of like wrapping it in saran wrap) and will cause it to buckle & break.

If you use vanilla to paint with luster dust, it will make the item sticky because it isn't high enough in alcohol to evaporate immediately (like lemon extract or Everclear alcohol). If it's humid, it can stay sticky almost forever. If it stays sticky, then it isn't dry, or drying, from the inside, either.

If you make an item out of pure gumpaste, you can dry it under a heat lamp, oven light, and/or fan pretty quickly. With the fondant in it, you can do the same thing, but you have to be careful because too high a heat will cause the item to melt before it dries.

HTH
Rae

can I use plain fondant to make a crown?

AI do not think it will be stiff enough to hold the shape. Fondant with tylose is what I would use.