OpticzBlacklight Reactive Invisible Blue Ink Industrial UV Marker

Works great, can't see a think unless under black light, easy to use

This item enables us to covertly ensure a client who is claiming to have received unusable product too frequently is actually being honest and not defrauding us or our supplier

Very thick tip makes it hard to write anything clear. It’s really bright initially but the brightness under UV faded more than I expected it to and although it does remain visible it remains a far cry from very clearly standing out.

I used this on metal surface and it applied and stayed on very well. Worth the money.

Don’t buy it. Does not work at all I have a very strong black light when I say it doesn’t work I mean it really doesn’t work at all does not close or show up any sign at all when you put a black light to the end it might as well be water I think Water would actually show up rider under a black light and then whatever liquid they have init

This marker does not work well on paper, works fine on plastic and cardboard.

Works great with Infray UV light. Opticz is bottom in pic.

Just received this. I wrote with it on white paper and it worked just fine.**Only thing to consider when I used a different UV pen on colored paper, my "invisible" ink showed up a little bit. Consider than when you're writing on paper.