Royal Icing

1.Beat all ingredients together in a bowl with a mixer until stiff and peaks hold their shape when beaters are lifted out, about 4 minutes. Transfer to a resealable container.
2.To tint, spoon small amounts of icing into bowls. Prevent "overcoloring" by squeezing droplets of food coloring onto a toothpick, then stirring in the color. Repeat as necessary until desired intensity is reached.
3.To thin icing for "flooding" stir in water until icing flows from a spoon in a thick ribbon. Use icing to decorate cookies. Tightly cover extra icing to keep it from drying out.