Electrofax papers were made by making use of various kinds of Zinc Oxide six kinds of Zinc Oxide were examined.
Their components, size distributions and origins are known.
These Zinc Oxides were manufactured by the socalled French mathod or American method.
Both kinds of Zinc by electrolysis or distillation were used in French method.
After charging our fax papers by 6000 valt coronal discharge, the dark and light decay curves were obtained and analysed.