A thorough investigation has been made of the problems involved in using a dye film dose meter for precision dosimetry at high doses, using both low- and high-LET radiation. The study includes: time course of coloration following irradiation at various dose levels; dose response after irradiation in vacuum or at atmospheric pressure; dose response dependency of temperature during irradiation and dose rate effects at high doses. The dose response characteristics have been measured mainly at 510 nm and over a dose range from 1 kGy to 104 kGy, which ranges from the lowest detectable dose to saturation of coloration. The dose response has been found to depend strongly on: the time span between irradiation and measurement; the irradiation temperature; and the dose rate at doses above 50 kGy for low-LET radiation. Irradiation in vacuum (right-pointing angle bracket1 Pa) and in air produced the same dose response. This work supplements previous investigations of the dye film, which were mainly carried out at lower doses.