A process for protecting a glass substrate coated with an electrochromic stack, includes depositing a temporary protective layer on the electrochromic stack, the temporary protective layer including an organic polymeric matrix and having a thickness of between 1 μm and 30 μm, and the temporary protective layer being removable by heat treatment at a temperature of between 300° C. and 500° C., fora period of between 180 s and 240 s.