Blend confectioners' sugar, water and extract until good piping consistency; add 1/4 to 1/2 teaspoon more water to thin slightly, if needed. Write messages or draw designs such as small hearts on each. Let dry thoroughly, at least 5 more hours. Store hearts in an airtight container with waxed paper between layers, at cool room temperature, for up to 1 month. Makes 36 hearts.