Different Luminous Invisible Ink
Recently, many customers asked me, "Can your contact lenses see my UV invisible ink pen?" My pen is like this:
At the first, we asked them, "Is your pen a UV invisible ink pen?", the answer always "YES". Okay, this seems all right. But if you order, you will find the one you receive can't work, they can't help you to see the marks your UV invisible ink pen made, but you sure that you use the UV flashlight to detect, the marks are very clear. What happened?
All of them are because of the variety of invisible ink. When you search invisible ink online, you will find there are luminous ink, blacklight ink, fluorescent ink, infrared ink, UV ink. It is easy to distinguish the UV ink and infrared ink, and people know what is the different between them, but others? I bet 90% people not very know the differences. When you buy the invisible ink pen in a store and ask the owner of the shop whether the one you select is UV invisible ink pen, and the answer is Yes. However, this UV pen is different from the one for UV contact lenses.
If you ever used the laundry detergent to clear your clothes, when you use the UV flashlight to illuminate the clothes, they are some luminous bright dots on the clothes; these are the fluorescent powder, which is said not well to human health. What is the relation between the UV invisible ink pen and this phenomenon?
Usually, the UV pen you buy online and local store which can be write in white paper while the marks is invisible to naked eyes is because the invisible ink of your pen is fluorescent inks, not the UV luminous ink for the marked cards contact lenses. The key point of the UV fluorescent ink pen is to add visible fluorescent complex with UV excitation to the ink. Through absorb light energy, the energy level transition of the atom is generated, and then the additional energy absorbed is released. Fluorescent ink have fluorescent agent, when it is exposed to ultraviolet light (sunlight, fluorescent lamp or mercury lamp), the fluorescent effect will be produced and which emits white light, giving the color a glaring fluorescent feel. The fluorescent ink have the visible type and invisible type, the main characteristic is have the fluorescer, the basic theory here is that it is emits visible light under UV irradiation. The key point is, The Fluorescent Ink Only Emits White Light When Illuminated With The Ultraviolet Light. If you use the marked cards contact lenses to detect them, the only result only can be "Your lenses don't work!"
The ink to mark cards is not suitable to mark on the white paper, as we know, there are thousands of kinds of playing cards in market, and all of them have different materials, colors and back patterns. To mark them, we need to develop the specific ink to match the color and the pattern on the backside of each kind of cards. It is means, before marking a deck of cards, we need to develop the specific invisible ink to mark them and the ink is the one can be work with the invisible contact lenses or UV glasses. Different invisible ink recipe need to mix with different materials, they are specific. Some people want to use the invisible ink to mark cards during the casino games, this is not suggest because the ink is easy to be found by others, what is more, the effect is not good.
If you read this message, I hope it will give you some help to know more about the UV invisible ink pen (can be said as black light pen), and know the distinction between the UV fluorescent ink and our special luminous ink for contact lenses.