Urgent! ! ! How to save movie ticket stubs?

The powder on the surface of thermal paper mixes and develops a color reaction under heated conditions. The colored writing on the thermal paper is unstable and easy to fade, making the content difficult to read. It should be kept away from high temperature and humidity, direct sunlight, and contact with solvents, plasticizers, etc., so that the storage time will be longer, but ordinary thermal paper is not suitable for long-term storage.