Cream of tartar
Sift the entire pound of sugar to remove all the lumps.
Place egg whites in mixing bowl and add sugar and cream of tartar to whites while stirring.
When all the sugar is incorporated, using an electric mixer, beat until thick and very white. Mixture will hold a peak.
This should take 5-7 minutes.
When finished, cover icing tightly with a damp cloth or plastic wrap as it dries very quickly and will form a crust.
To tint icing, use a small amount of color at a time.
Paste food colors will not change the consistency as liquid colors will.
For a quarter cup of icing, dip the tip of a toothpick into the color, then into the icing. Stir well.
If you desire more color, dip again. Proceed gradually.
For strong colors like red, royal blue and dark purple, you will need 1/8 teaspoon to 1/4 cup icing.
Note: If you plan to make several colors, a muffin tin makes a handy palette.