Knowledge Base

How to Make a Blacklight (Homemade with Torch or a Light Bulb)


How to make a black light is so easy and so fun when done. Follow my simple step-by-step guides, using a variety of light sources, to make your DIY black light.

Blacklights can be used for many things, including checking for forgeries, checking hand stamps at clubs and theme parks, or even finding leaks. However, making your own black light is for fun use, more along the lines of the lights you see in clubs and theme parks.

Making them great fun to have at parties, for drawing on t-shirts, or to design a great piece of art on a blacklight poster. The entertainment is endless.

How Does a Black Light Work?


A blacklight source only emits ultraviolet light or UVA light, which the human eye is unable to see until it shines on objects containing phosphors.

Even then we are not actually seeing the UV-A, but the light reflected back, in the form of glowing colors. Why not check out how a blacklight bulb or fluorescent light works to find out in greater detail about these types of lights.

The fluorescent (purple) tube lights, similar to those you see at concerts and nightclubs, contain an inert gas and mercury along with an outside layer of phosphors. The phosphor layer is what absorbs our visible light (UVB) leaving only the ultraviolet light shining through.

Ok, that’s the technical bit over, now I’ll tell you how to make blacklight (how to make ultraviolet light). Don’t panic and run to the shops, the chances are you’ll have all materials you need lying around the house.

How to Make a DIY Black Lights

To make your own blacklight using regular household materials. You only require a light source, some colorful highlighter pens, and clear tape.

Here I’ll explain the different light sources that you can use, along with how to make a blacklight with your phone and other DIY blacklight ideas.

1. How to Make a Blacklight Flashlight


When making a homemade black light, you are making UV light visible. The easiest way to do this is with LED flashlights.

Materials Required:

  • Cling wrap or clear cellophane
  • Rubber bands
  • Blue & purple marker pen

Method Used to Make a Black Light Flashlight

Please note: to avoid the cellphone or cling wrap melting use a low-powered or LED flash light.

  1. Cover the flashlight lens with cling wrap/ cellophane (Be sure to have surplus around the edges to allow for securing).
  2. Secure by placing the rubber band around the flashlight and surplus cling wrap (you could also use a piece of tape to do this).
  3. Color the part over the lens with the blue marker (you may find this is easier if done before placing it over the flashlight).
  4. Repeat steps 1-3 for the second layer.
  5. Repeat step 1-2 for the third layer but now coloring with purple marker.
  6. Alternatively, you can skip the coloring and use blue and purple cellophane, instead (often found being sold as wrapping paper in stores).

That’s it, simple eh, you can now go and find things to do with a black light. Enjoy.

2. How to Make a Blacklight with your Phone


How to make UV light with your phone basically follows the same steps as on a flashlight. Only this time, you are using the flashlight feature on your phone

Although this is a little more tedious( because you don’t want to cover up the camera lens). Unfortunately on a lot of phones, they are right next to each other, don’t worry you can easily clean the lens.

I often get asked if you can use special iPhone black light tape, no it doesn’t exist. Or, if it does I have yet to be able to track some down.

Materials Required:

  • Clear/translutant tape
  • Blue and purple marker

Method Used to Make a Blacklight with your Phone

  1. Cover the light with one piece of tape
  2. Color the tape blue
  3. Repeat steps 1 & 2
  4. Now place the final layer of tape
  5. Color this purple

That’s it guys, you’re up and running with your DIY black light.

3. Make a Black Light with Your Flash


This one is for any keen photographers out there, yes it’s black lights for photoshoots. Being a keen photographer, I think I have saved the best till last. I love it anyway.

Learn how to make a black light from a flash is a must if you want to get some amazing shots.

For this one, I am not going to run through all the steps. You have the idea already from the two examples given above.

That’s right, get 3 pieces of cellophane or equivalent and color 2 blue and one purple and carefully attach to your flash unit. Watch this video to see it done for real.

Now it’s down to your imagination.

Fun Things to do With a Blacklight

Making a black light flashlight is a great project for kids. You can create a black light poster with special shapes and messages to decorate their room or plan a spy-themed scavenger hunt for a birthday party they’ll never forget.

Why not throw a black light party, you can use the same method as above to easily convert LED light strips into blacklight.

Really, the uses are endless.

Frequently Asked Questions (People Also Ask)


I hope you have enjoyed learning how to make and use backlights. But before I leave you to it I’ll answer a few questions that people often ask about blacklights.

Is there a black light app that works?

If there is a black light app that works, I have not managed to find it. I have seen a couple, but they both had very poor ratings. I for one was not prepared to pay to find out if they did actually work.

What will show up under a blacklight?

Material containing phosphors will show up under a blacklight and the list is long. From forgeries to urine stains, if there are phosphors around they will glow.

Here are a few more examples of glow-in-the-dark items. vitamin A and B pills, laundry detergent and petroleum jelly. Remember a DIY blacklight is for fun, you will need to purchase a blacklight bulb for serious use.

Is there a difference between UV light and blacklight?

A blacklight is a type of UV light, but they are not the same thing. There is a spectrum of ultraviolet light and blacklight is a nonvisible light, one that the human eye is unable to see.


Homemade black lights are easy to make and great for enjoyment and entertainment. Yes, they work and I think work well, remember, a black light is expensive and there is a reason. Please do not expect the same results from a homemade version or use it for serious purposes.

Related posts

How Much Do LED Lights Save Per Year?

David Willis

Softbox Vs Umbrella Lighting – Photography Comparison

David Willis

LED vs Halogen vs Incandescent Bulbs

David Willis

Leave a Comment