The front of the banknote
Under standard UV light, you will see fibres embedded in the paper. Each fibre shows three different colours. Various parts of the note glow in yellow. The paper itself remains dark and does not glow in blue.
If you use special UV light (UV-C), a large € symbol becomes visible in the centre of the banknote.
The back of the banknote
Under standard UV light, a quarter of a circle will glow in green. The horizontal serial number and a stripe will appear in red.
Note: Counterfeit notes with UV imitations are hard to distinguish from genuine notes if you use a UV lamp. Also use the look, feel and tilt method to check the authenticity of a euro banknote.