Economical, lasts a long time, not red

For the product I use a blank stamp pad and fit Naturally a stamp.
It adheres without problems on the skin and very long lasting (even after several Handwaeschen with soap still traces visible).

Also positive: It's scary productive.
I dare not extrapolate how many stamps units ranges the vial, but there will certainly be many thousands.

The only question mark:
The delivered color is indeed obvious to the human eye already red, excited by UV color is definitely blue.
I'm not sure if that is the nature of duennfluessigen fluorescent colors or on my lighting.

Otherwise: Good product