The cosmetic system ofwater, lecithin,polyethylene glycol (M.W. 5000), and white oil was studied and the phase diagram determined using visual observation, low angle x-ray diffraction and chemical analysis.The results showed the lecithinI water lamellarliquid crystal to be retained when the polyethylene glycol was gradually replaced by white oil. The polyethylene glycol was solubilizedin the lamellarliquid'crystal to a maximum level of 10%, the white oil to 8%.The evaporation rate, from a thinlayer, was followed gravimetrically. The existing structures as the evaporation proceeded were identified optically. Evaporation ofwater from the three phase emulsion lead to crystallization ofthe polymer in the previously existing water droplets, leading to a four phase system of polyethyleneglycol, polyethylene glycol/water, LLC, and white oil.A dramatic decrease in the loss rate of water was observed when all four components co-exist in equilibrium.