Gumpaste is a malleable, edible clay for making realistic models of items, such as flowers and leaves, with which to decorate a cake or cupcakes. It's used often in cake decoration because it can be rolled out thinner than fondant, which allows you to mold it more delicately than you can fondant. However, it still retains a bit of flexibility unlike another edible clay, pastillage, so that it is less likely to break. Its vital ingredient can be tough to find, but you should be able to locate its synthetic version at craft stores.
Pour 4 tbsp. lukewarm water into your mixing bowl and dissolve the packet of gelatin into it.
Stir the glucose into the gelatin and water mixture. If the room you are working in is cool, microwave the glucose for 20 to 30 seconds to loosen it. Stir in the glucose until you have a uniform mixture.
Add in the gum tragacanth, Gum Tex or tylose powder. Then stir in the sugar, 1 cup at a time, until you have a soft and sticky dough.
Place the dough into a sealable plastic bag and seal it, trying to push out as much air as possible. Let sit overnight.
Knead a bit of powdered sugar into your dough to stiffen if it's too soft or sticky for you to work with. Roll it out thin and use cookie cutters or cake tools to create your decorations.