I've recently started working with marshmallow fondant. Last time I covered a cake with plain white MMF and it worked like a charm and looked beautiful! Yesterday I covered a cake with MMF that I tinted blue with the wilton gel. After I was done it looked pretty good. I sealed it in a cake saver. Today when I opened it, it has dimples and looks like it stretched or slid down the cake a little- there are small folds at the bottom. Any ideas of what I did wrong so I can learn from my mistake? Thanks in advance!!

Sealing it in a cake saver, if it's air-tight, might've been the problem.

Maybe I added too much crisco? Is that possible? I'm not going to seal it next time to eliminate that factor. As far as thickness- I used the orange guide rings on the 20" wilton rolling pin which makes the fondant 1/8" I believe. Is that about the right thickness? It worked last time so I just repeated the same procedure this time.

1/8" is great, not too thick at all...

How much Crisco did you add?
I use 1/2c, I melt it right in with the marshmallows.

Maybe too much Crisco...I use just enough to coat bowl when melting marshmallows and just a bit to keep it from sticking to my hands and mat i mix it on...I find the less I use the better especially when adding color to it.

1/2 cup is way too much. Like the other poster I use a total of about a heaping teaspoonful and sometimes I don't use any at all and it comes out beautifully. The dimples are trapped air bubbles that popped and made caved in areas. The sagging at the bottom is because 1.) your MMF wasn't stiff enough and stretched 2.) your cake settled over night and ended up shorter than when you applied the fondant What I do is roll out the fondant, pop all the bubbles then ball it back up and reroll on more powdered sugar. I find that rolling out colder MMF results in fewer bubbles, but it's hard on the wrists because of how hard you need to push down on the acrylic rolling pin.

Thanks, guys!! I don't add any crisco to the actual MMF recipe- it's just marshmallows, Conf sugar and a bit of water and vanilla. I just grease my hands and board with the crisco, but thought maybe I got carried away with it. I don't know why it never occurred to me that the cake may have settled.. That's definitely possible. I also did pop several air bubbles. I really appreciate all the tips. I'd definitely rather learn from my mistakes so I can make the adjustments necessary.

Update: I made another MMF cake yesterday and I kneaded in a lot more PS than last time to make it stiffer. Turned out beautiful and still looks good this morning!! Yay!!