Invisible Ink Pen, Daemson Spy Pen with 3 PCS Mini UV LED Keychain Flashlight, Disappearing Ink Magic Pen with Black Light Markers for Secret Notes, Fit for Christmas Halloween Holiday Gifts (3 PCS) | Disappearing Ink Magic Pens with Black Light Markers for Secret Notes, Fit for Christmas Halloween Holiday Gifts (3 PCS)

I don't really see a difference between the blue and yellow under the UV light (probably because it's blue) but the pink is very pronounced. Tried it on paper and faux leather so far and it takes a second to fade, but it isn't visible after it dries. On the paper, the pink marker left a very slight impression that you would not be able to see at a glance but if you look hard and know exactly where it is, you can see a small color difference. Haven't tested on other surfaces but so far, so good.

Fun toy

We did a scavenger hunt and this worked marvelously! We absolutely loved the invisible ink - it showed up so well! Pros: - The pens work great - The lights actually show the invisible ink. - That are durable and last well - They are just so fun!!! Cons: - The marker tips are on the thicker side so writing small is not an option. - The ink does run if it gets moist or wet. This is a great price for the awesome item you get - I would highly recommend purchasing it!

Great little fun way to write messages. The colors do not "pop" out really they are all kind of the same. The blue did not look blue at all so I gave it 4 stars but you could see it under the black lights just did not really look blue. If you are looking for the specific colors these are not going to give you what you are looking for. If you are looking for pens to write messages that can only be seen under a black light they will do the trick.

These worked well for notes from Santa on Christmas morning. Kids love the magic of invisible ink.