I have a cake I am doing for a friend and I need her initals standing up on top. I don't need cutters or anything I just need to know which would be better, gumpaste or fondant. And how long do they need to harden?

It depends on how humid it is in your area. I have made many from straight fondant w/o problems.
Actually a 50/50 mix of the two is perfect
I would give them as long as possible to dry....like make them now

I use funky ole wilton fondant with gumtex and have had wonderful success. Definitely let them dry as long as possible. Definitely at least 24 hours.

I would go with gumpaste. It will dry rock hard for sure, reguardless of weather.

Hi Muse...I live in North Ga and I have used a half and half mixture of fondant and gumpaste and you have to let it harden for about 2-3 days because of the humidity in Georgia. Happy Cakin'!

I would go with gumpaste or else knead a bunch of tylose or gumtex into your fondant...