Process for preparing porous fluoropolymer films

A process for preparing a porous film of a fluoropolymer, comprising the following steps:

• the provision of an ink comprising the fluoropolymer and a vehicle comprising a solvent for the fluoropolymer and a nonsolvent for the fluoropolymer, said solvent for the fluoropolymer and said nonsolvent for the fluoropolymer being mutually miscible;
• the deposition of the ink on a substrate;
• the evaporation of the vehicle comprising the solvent and the nonsolvent;
• in which:
• the nonsolvent is chosen from the group consisting of benzyl alcohol, benzaldehyde or a mixture thereof;
• and
• the solvent has a saturating vapor pressure at 20° C. higher than that of the nonsolvent.