Combine all ingredients together in mixing bowl.
Beat on low speed with whip attachment until combined then increase speed to medium-high and beat for 5 – 8 minutes, adding 2-3 tablespoons more warm water, as necessary. Icing should be stiff enough to hold a peak when tested. Use this thick icing to outline cookies.
Use royal icing immediately. if you have left over icing, store at room temperature on an airtight container up to 2 weeks.