UV Blacklight Reactive Large Tip Invisible Ink Marker, Yellow

With the black light the ink showed up nice and bright for our Escape Room

I bought this to help make UV geocaches. The ink works great, and I believe it works as intended, but it seems UV ink on paper can smear if it gets wet. Easy to use and read with a UV light.

Used this in a student project with our robotics class to create an “escape room”. We used it on a blackboard in a dark area, with some text written in chalk and the other text with this pen. It worked great.

The marker writes really well and shows up great with a black light, but it’s not totally invisible. If you were playing a game with kids or something, they can see the written material without the light. It looks like a very light highlighter. I still like it though.

I bought this to put duplicate hidden numbers on documents. It works very well. On the first few uses, the tip has a little more ink than needed, but I solved that my standing it up with the tip at the top. Don't expect as much coverage from say a Magic Marker or Highlighter. This has started to dry out after writing 350 half inch tall numbers. I ordered some more so I can finish my documents consistently. If you do not have to write with it and only need to mark, consider buying a small bottle of UV ink for a stamp pad, a non inked pad, and a rubber stamp with a suitable shape. I ordered all these from Amazon for the cost of two of these markers. This did work exactly as promised, and I am pleased with how they work. I also highly recommend the "Dark Dawn" UV B light sources. They are true UV B, rechargeable, have a good run time, and you cannot beat the price!