Glow For It: How To Design a Magical T-shirt Using Glow-In-The-Dark Ink
March 26, 2021
Of all the various specialty inks out there, only one is visible in a dark room: glow-in-the-dark ink. This effect is all-too-often overlooked, which is odd because it can make a T-shirt design become magical when the lights go out, eliciting ooo’s and ahh’s from anyone in proximity. And if done creatively, it can transform the design into something unexpected.
So what’s the best way to incorporate it into your design? In this post, I’m going to show you examples of ways to use it, and answer some of the frequently asked questions. But first, I’ll quickly explain how this sorcery works. Ready to glow?
How glow-in-the-dark-ink works
Glow-in-the-dark ink is one of many photoluminescent products. If you were lucky enough as a kid to have the glowing galaxy sticker set, your room magically turned into a sea of stars and planets when the lights when off at night.
All of these products, including screen printing ink, owe their eerie glow to phosphors – a type of chemical compound that absorbs energy and re-emits it as visible light. Zinc sulfide and strontium aluminate are two of the most commonly used phosphors for photoluminescent ink as they re-emit energy over a long period. They can be mixed in with plastics– or ink!
When you shine a light on a glow in the dark object, the incoming photons (packets of light) excite the phosphor molecules. Very exciting. These molecules release the energy they’ve stored slowly by giving out photons, creating that dim glow.
How to use glow-in-the-dark-ink in your design
Below are five ideas I came up with to use as examples, giving you some direction or inspiration for your own design. Remember that glow-in-the-dark ink can add an extra dimension to the image when it’s activated. Use your imagination to come up with creative ways to use this extra-special specialty ink. (Imagination not included).
One important thing to know is that glow-in-the-dark requires an underbase on black or color garments. Depending on the amount of ink deposited, it may not be visible at all without an underbase. You can print directly on the shirt without an underbase, but the effect is reduced significantly.
Think of it this way: the canvas for your glowing part of your design is the white ink underbase. The artists among you should take that as a cue and use it to your advantage. Look at my example idea #5 for an idea for incorporating this into the design.
Example Idea #1
Cover all the white in a design with glow-in-the-dark ink and watch it come to life at night. This is the most straightforward way of using this ink. The design stays the same, but every part of the print glows. Maximum photoluminescence!
Example Idea #2
Strategically add highlights to some parts, keeping the design the same, but emphasizing areas to make it look striking in the dark. Keep in mind: the contrast will change. Parts with glow-in-the-dark ink will be the brightest– even white ink will be darker.
Example Idea #3
Take a well-known image and add a twist that only appears in the dark. This is one way you can really get creative with a glow-in-the-dark concept. What secret image will be revealed when the lights go out? That’s up to you.
Example Idea #4
Create a message with text that has a hidden secondary message which only becomes apparent when the glow is activated. I made the design below, but the concept is not my original. It’s a message sold on T-shirts all over the web, so I don’t know who to credit. But you should come up with your own inspirational message, clever pun, or bad joke.
Example Idea #5
Omit the underbase beneath some areas of the glow-in-the-dark-ink, creating a duotone of glow. Parts of the design with underbase will be much brighter than parts without it. There are many ways to use this technique. And keep in mind that the glow will be very dim without an underbase, so make sure anything that needs to be visible has an underbase.
How to print with glow-in-the-dark ink
Here’s a video by my colleague Dan Leer showing you our process and explaining how we made this print work. One thing to pay attention to is how the underbase plays a crucial role, and how to take the daytime look of it into account when creating your design. It also shows you the different glow colors you get under a blacklight vs the normal glow-in-the-dark.
Frequently asked questions about glow-in-the-dark ink
Does it cost more?
No. We can’t speak for other printers, but with us, the price for glow-in-the-dark ink is the same as any other ink.
What kind of light does it need to charge?
Any kind of light. Direct sunlight will charge it the fastest, but a direct, bright indoor light can work almost as well.
How long does it take to charge?
Direct sunlight, only 5 minutes. On an overcast day, maybe 10. Indoor lighting can take 10-30 mins to fully charge it. Ultraviolet light, aka UV light, aka blacklight, will charge it as well– it will also make it immediately glow super brightly.
How long does the effect last?
It depends on many factors, including the light used to charge it. The effect can last for hours, but it slowly diminishes. This can be profoundly sad as the magic fades away. Keep a light source nearby so you can stay charged up (and happy).
Why is most glow-in-the-dark stuff green?
The human eye is most sensitive to green light, so the glow appears brighter and is generally favored by manufacturers. This is also why night-vision goggles and radar screens (also powered by phosphors) are typically green.
What glow colors are available?
Glow-in-the-dark ink is typically available in green, yellow, orange, pink, purple and blue. Side note: the standard green is also called “off-white” because of how it looks in the light.
Is it the same thing as dayglo?
No. Dayglo refers to fluorescent colors, which look ultra-bright and saturated in the daylight. Also known as neon colors.
Does it work on top of other ink colors?
Yes, but you want to be careful here. It will work well on lighter, brighter (and matching) colors like green and yellow. On top of other colors, it will have some mixed results and on dark colors, it may not work at all. White underbase is your best bet.
Does it work on white tees?
Yes, but I don’t recommend it by itself. The reason is that it will give the T-shirt a slightly yellow/green tint in the day time, which could look awkward. But if you’re hiding it among other colors for a nighttime surprise, then glow for it.
If you have any questions about glow-in-the-dark ink or how to use it in your design, don’t hesitate to give us a call or chat. Our Sales team can help you with the order and our Art team can help you with the design.
When you’re not sure which direction to go… let it glow, let it glow, let it glow.
About the Author
A graduate of the Multimedia program at the University of the Arts in Philadelphia, Imri Merritt is an industry veteran with over 10 years of graphic design and color separations experience in the screen printing industry.