I am going to make a Ninja cake for my son's birthday and want to do a sword on it - going from one side to the other.  Should I just make it out of gum paste or should I mold it out of rice krispie treats and then cover with gum paste or fondant.  Any other suggestions or photos?  Any ideas much appreciated.

thanks

I think it depends on the size of the sword you want. A ninja-type sword is usually long and thin, so it might be alright to make it out of straight gum paste. RKT just seems like it would make it denser and harder to support. And make sure to keep support in mind. I'm thinking that you could just make each end slightly longer so you have something to stick into the cake.

I made a Deadpool  Ninja cake with the swords going thru the cake. I used fondant but gumpaste would  harden quicker. 

If you are interested in seeing how I did it I have a Youtube video: