When someone describes the constitution of an item as including things which are not actually things. Not just fictional things, like "hen teeth", but abstract concepts like "exuberance" or intangible ones like "the sound of a cat's footsteps". Expect these items to be kept in jars or bottles and take the form of liquids or luminous gases. Be especially careful with anything Made of Evil. A subtrope of Eye of Newt. See also Made From Real Girl Scouts. Examples of Insubstantial Ingredients include: