Gum paste -- also known as modelling paste -- is an edible substance used to form decorations for cakes and other desserts. Unlike fondant icing, gum paste can be rolled very thin, making it perfect for creating delicate designs, such as flower petals. The addition of tylose powder gives the gum paste its pliability. Occasionally, if the paste has sat out for too long, it hardens and needs to be softened so you can work with it more easily.
Remove the gum paste from the packet. If the paste has been in the fridge, allow it to cool to room temperature before working with it. Using your bare hands, knead the paste as you would dough. Push the paste in with your fingers, fold it over and work it into itself, making it warm from the touch of your hands.
Add the gum paste to the microwave if simply kneading with your hands does not soften it enough. Place it in a microwave-safe glass bowl and heat for five seconds at a time to avoid overheating or burning the paste. Continue to microwave in five second increments until the paste softens. Use this as a last resort if hand kneading does not work.
Roll the gum paste out onto the counter once it is pliable enough to work with. Sprinkle icing sugar on top of your counter to keep the paste from sticking to the surface. Using a rolling pin, spread the paste out evenly and thinly so that you can cut out your desired shapes for modelling and painting.