Sorry if this is an elementary question. I have looked everywhere on CC for the definitions or differences, but I'm not finding the answer.

Are they interchangeable? Why would you use one over the other when making decorations? Do they mold similar? Or do you only use fondant to roll thin and cover cakes or do flat decorations like geometric shapes? Why would you combine the two forms (mix together before making a decoration)?

Does one dry harder? Does one dry faster?

Any information would be helpful!

TIA

Fondant is basicaly a covering medium, it doesn't hold up to shaping freestanding pieces - apart from podgy modelled figures. Gumpaste has additional chemicals added, such as CMC or tylose, to make it firmer and better for holding shapes like bows, flowers etc. You can roll gumpaste thinner and have it hold it's shape.

Thanks so much for asking that question... I was wondering the same thing, but was afraid to ask.
I've used fondant, never gum paste, but want to do molding/ sculpture work.

Thanks again for the info.

emmascakes, that was a perfect answer!

I'll add: fondant (especially MMF) is tasty. Gumpaste isn't.