1) The separating agent will affect the ink of the thermal transfer film. If the release agent is too tight, you can print by increasing the temperature; if the release agent is too loose, it is easy to print, but it will cause the ink to stick back.
2) If the thermal transfer film is squeezed during storage, it will easily cause the ink to stick back.
3) The storage environment should also be paid attention to. Humid environment and high temperature will cause the ink to fall off the film.