I am making my daughters christening cake and don't want to rush it so was thinking about making my fondant 3d figures in advance, how long will they last once made and what is the best way to store them?

Hi there, I wouldn't use fondant only. I would mix 50/50 gumpaste and fondant or add CMC/Tylose to fondant.

Once they are made you can keep it forever. You need to store them in an airtight box and out of direct sunlight.

To add to what bashini said though, do not store them in an airtight box until they are completely, 100% dry. Trapping the moisture in can ruin them! Their only enemy - other than sunlight as mentioned - is humidity...well maybe pests but I don't know if pests go for gumpaste. Personally I would store in a cardboard box in a dark cupboard.

And I agree, I use 50/50 for figures meant to last, and yes, you can make them now! I still have the Remy from my avatar, and he is 2 years old! Mind you he's missing all of his appendages, ears, nose...etc. (lol!) after being subjected to playtime by my 3 year old...but he is still as solid as a rock.

I don't store mine in an airtight box at all. The one time I did the dot of color I used on the eyes bleed. Everyone I have put in a cake box have been fine with.

I've had some for years before I finally threw them out. I wouldn't have eaten them then but then again I wouldn't have eaten right after I made them since they are hard.