Prepare a large baking sheet by laying down lightly oiled parchment paper. Sprinkle a bit of icing sugar on the parchment.
In a large mixing bowl, combine dry gum paste with water and peppermint flavoring. Blend ingredients together until a dense paste forms.
Spread the paste evenly onto the baking sheet and coat the top of the paste with what is left of the icing sugar.
Using cookie cut-outs or other tools, you can mold your mints into any shape you desire. Some people roll the paste into tiny balls. You can also create mints of different sizes.