Protective cap for surface treatments on eyeglass frame portions comprising: - at least one between a temple and a front; and - at least one hinge element fixed to said at least one between said temple and said front; said protective cap comprising: - at least one first protection element, which is provided with a first coupling portion and is intended to be mounted to cover said hinge element, in order to protect it during surface treatments; - at least one second protection element, which is provided with a second coupling portion, mechanically and removably connected to the first coupling portion of said first protection element, and is intended to be mounted to cover a surface zone of said one between said temple and said front, adjacent to said hinge element in order to protect it during surface treatments; characterized in that at least the first coupling portion of said first protection element is made of a first polymer material provided with a first swelling, and that at least the second coupling portion of said second protection element is made of a second polymer material, provided with a second swelling, wherein said second swelling is greater than said first swelling, said second protection element being intended to be separated from said first protection element due to different swelling following the absorption of a rinsing fluid, wherein said second polymer material is substantially insoluble in said rinsing fluid. - at least one between a temple and a front; and - at least one hinge element fixed to said at least one between said temple and said front; said protective cap comprising: - at least one first protection element, which is provided with a first coupling portion and is intended to be mounted to cover said hinge element, in order to protect it during surface treatments; - at least one second protection element, which is provided with a second coupling portion, mechanically and removably connected to the first coupling portion of said first protection element, and is intended to be mounted to cover a surface zone of said one between said temple and said front, adjacent to said hinge element in order to protect it during surface treatments; - at least one first protection element, which is provided with a first coupling portion and is intended to be mounted to cover said hinge element, in order to protect it during surface treatments; - at least one second protection element, which is provided with a second coupling portion, mechanically and removably connected to the first coupling portion of said first protection element, and is intended to be mounted to cover a surface zone of said one between said temple and said front, adjacent to said hinge element in order to protect it during surface treatments; characterized in that at least the first coupling portion of said first protection element is made of a first polymer material provided with a first swelling, and that at least the second coupling portion of said second protection element is made of a second polymer material, provided with a second swelling, wherein said second swelling is greater than said first swelling, said second protection element being intended to be separated from said first protection element due to different swelling following the absorption of a rinsing fluid, wherein said second polymer material is substantially insoluble in said rinsing fluid.