Because alkyl silicones have a lower surface tension than hydrocarbon based molecules, coupled with their amphiphilic structure (silicone and alkyl groups in the same molecule) means the addition of properly chosen alkyl silicones to oils results in a lowering of the surface tension from the 30 dyne/cm into the range of 20 dynes/cm. The consumer is able to differentiate the skin feel of two oils differing in surface tension by as little as 2 dynes/cm. The result is a more siliconelike feel (siliphilic). The implications of this to the cosmetic formulator need to be understood clearly. The cosmetic elegance of a product can be altered dramatically by addition of low concentrations of properly chosen silicone compounds, resulting in products that consumers perceive as very different from the base formulation, lacking only the added silicone. As an example, hydrophobic serum based on a fatty ester can be rendered more spreadable by addition of less than 1% alkyl silicone. This improved spreadability and lower surface tension will be perceived by the consumer as a less hydrophilic serum.