his work is focused in the application of RESS process to coating where the SFC is the unique solvent. The first to use a RESS process for coating reasons were Debenedetti et al. [12] in 1993, using SC-CO2 as solvent, while the carrier material was agitated in a stirred tank reactor. Since then, different alternatives have been developed, such as rapid expansion from supercritical solution with a nonsolvent (RESS-N) [13] and [14]. Because of the low solubility of the most part of polymers in SC-CO2, cosolvents are used to enhance solubility of the polymer in the supercritical fluid. At atmospheric pressure, these cosolvents are nonsolvents for the polymers, consequently, they do not swell the polymer product during expansion and adhesion is not expected. For polymers, it has been demonstrated that cosolvents that cause a large increases of solubilities in CO2 need not be good solvents for the polymer. Ethanol is the most used cosolvent