Prinz Portable UV Test Lamp, Short Wave for Testing Phosphorescent Papers
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Prinz 2069 battery powered shortwave UV test lamp 256nm wavelength for Phosphors of Great Britain, Israel, USA etc. Requires 4 x AA batteries (not supplied)For detecting Phosphor bands on stamps for best results we would recommend using the lamp in a darkened room, allowing you to see more clearly the difference between the Phosphor section and the normal paper of the stamp. Some Phophors also hold onto the UV light, and emit an afterglow after the lamp is switched off. If you are working on Machin definitive stamps after 1991, when the design of the perforations changed you will also need a longwave lamp. Do not look directly into any shortwave ultra violet lamps.