A typical graph of surface tension of a 1% solution of SLS (sodium lauryl sulfate) with differing amounts of silicone surfactant added is seen in Figure 4. While not having the clear break point observed with a pure surfactant at the critical micelle concentration, Figure 4 does resemble a plot of surface tension for a surfactant. The ability to alter the shape of the curve is critical to the economics of lowering surface tension. The curve is concave; the desired curve is convex, producing lower surface tension with minimal silicone (“greening with silicones”). Since a clear critical micelle concentration cannot be determined by The lower the RF50 the better able the silicone surfactant is to compete with the fatty surfactant for surface and the more efficient the silicone surfactant will be. This technique allows one to design molecules that will be optimised for a particular formulation. Not only can surfactant systems be evaluated, but also complex formulations can be evaluated by simply defining the fatty surfactant’s surface tension as the formulation’s initial surface tension. Not only surface tension, but also foam and the like can be tested and optimised by evaluating foam as the property rather than surface tension. Table 1 shows the RF50 values for specific combinations. The so-called RF50 value is a measure of the effectiveness in lowering surface tension in mixed systems. The lower the RF50 value the lower the concentration needed to reach a 50% reduction in surface tension between the two surfactants in a mixed system. The ability to lower surface tension is dependant on the type of oil chosen and how it interacts with the alkyl silicone added. Ethyl methicone, a low molecular weight silicone is much more effective in lowering surface tension than is cetyl dimethicone in olive oil. Ethyl methicone has an RF50 of 2% in olive oil, while cetyl dimethicone has an RF50 of 8% in olive oil. Figures 5 and 6 show the RF50 values.