Sodium Bicarbonate and Citric Acid are the two core materials in making your own bath bombs. The general rule in bath bomb making is to use a ratio of 5:1 or 3:1 Sodium Bicarbonate to Citric acid. The Sodium Bicarbonate is a powder form, whilst the Citric Acid is a very fine grain to give a superior finish. These two ingredients form the core materials of the bath bomb, and when dropped in water react together creating the fizz. These two ingredients can be bound together using several binding agents such as sweet almond oil or essential oils. And can be coloured using our water based colours. Why not add rose petals for a luxurious finish?