Could someone tell me what is better to put on the sides of a fondant cake, Royal Icing or butter cream the color will be black icing on red fondant.
Thank you

I think royal on fondant is more popular, but i've piped BC on fondant before, too. Use a good quality black food color ( i like Americolorm if you can get it) so it doesnt bleed. If you want to be on the safe side, go with royal.

Thank you, I will go with the royal I just did not want it to run down, I have not been working too much with it, this is all new to me. I really appreciate the help from everyone on Cake Central.

I like royal a lot, though just be careful when you're making it. As I'm sure you've read, everything that touches royal icing (bowl, beaters, etc.) needs to be completely grease-free. After washing everything in hot soapy water, I rub white vinegar over everything just to be sure there's no grease. Also, mix it for the right amount of time instead of taking shortcuts! Another good thing about royal (you can do this to some extent wiht bc, too) is using a lightly damp paintbrush to smooth uneven lines/joints before it's dry.

Good luck!