Fondant is a pliable sugar paste used to decorate cakes. You roll it to a smooth thin consistency and then drape it over a cake to cover it. Bakers also use it to mold shapes. You can purchase pre-made fondant, which contains sugar, glucose, vegetable oil, water, glycerine and corn starch, or you can make your own marshmallow fondant with marshmallows, water, confectioner's sugar, and shortening. While bakers use fondant because of its smooth professional appearance and ease to work with, it can at times pose problems.
Cracking can happen if you roll the fondant too thick or do not knead it enough. It can also crack if the fondant is too dry. Make sure to knead the fondant until it is smooth and tacky, and roll it to a quarter inch thickness so that it is not too heavy and doesn't weigh itself down. If your fondant is too dry, knead in some vegetable shortening. Fix cracks by smoothing in a circular motion or using a bit of shortening. Don't use water.
If you don't lay the fondant out carefully and smooth it well, you can end up with air bubbles. You can fix these by piercing them with a pin and then smoothing the fondant in a circular motion with a smoothing tool.
Fondant can become sticky if it's too warm or if you've handled it too much. If your fondant is too sticky to work with or roll out, knead in some confectioner's sugar. Prevent it from sticking to your hands by coating them lightly with shortening or powdered sugar.
Don't store unused fondant in the fridge or freezer. The temperature difference between the fridge or freezer and room temperature will create condensation, which will dissolve the fondant. Store it in an airtight container in a cool, dry location.