I am going to make a graduation cake and I was wondering if the black fondant will bleed into the red. Also, I was thinking of making MMF, but would the color hold up better in store bought fondant? I have to finish the cake on Thursday next week and it will be for a party on Saturday. I want to have it fully assembled on Thursday because I work 3rd shift Thursday and Friday night. Thanks for any help.

I've never had bleeding problems. I have bought bl and red becuase it's a pain to make. But it is also expensive. If you use a super red or black coloring in your MMF, it will be easier- you don't have to use as much. Americolor is the best, if you can get it. If not, your local hobby store will likely have another brand. Also, for your black, make choc MMF first - it's darker to begin with. And I add the coloring to my warm marshmallows so I don't have as much kneeding. HTH!

Thank you. I was thinking about making the chocolate MMF for the black, but I read that it cracks. Any tips to prevent this?

As long as you don't get the pieces you are gluing on you won't have any problems. I have worked with black, red and white several times with no problems. Just use a tiny bit of what ever you are gluing it with.

I made red MMF this way and it worked great.....
http://sugarsweetcakesandtreats.blogspot.com/2010/11/recipe-red-marshmallow-fondant-mmf.html

Good Luck!