Hardness and break strength are properties of a cosmetic product to withstand the normal (and sometimes abnormal) stresses that these products are put under or exposed to by the consumer. These two parameters can be approached from a formulation standpoint as well as a product testing standpoint. Usually we are referring to anhydrous waxy solids when we concern ourselves with hardness and break strength. The most common products that involve hardness and breaking are stick products, pencils and sometimes pressed powders. For stick-type products of any kind (lip, eye or foundation) the key parameter in judging its strength and hardness is its crystallinity. Crystallinity is the single most important factor in determining the acceptability of a cosmetic stick formula. For testing the acceptability of a solid cosmetic product, the following tests can be performed depending on the physical form of the product: Break point, Crush point, Melt point, Drop point or Hardness value. This article will discuss the different types of products where hardness and strength are the determining factors in their performance and stability...