How To Make A Black Light In Four Easy Steps

How To Make A Black Light
Credit: Black Light Theatre in Prague / Wiki Commons

Black lights, which are also known as ultraviolet lamps, can be used in so many ways. From identifying counterfeit money to authenticating antiques, and beyond.

We often see black lights in nightclubs, crime scene programs, haunted house shows, and much more.

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However, whether being used for fun or utility, it is worth noting that black lights work by making objects that contain chemical compounds fluorescent under the UV radiation emitted from the bulb.

If you’re curious about how to make a black light, follow these steps:

Supplies needed to make a Black Light

  • A Light Source: The essential component you need is a light source. You can use a light bulb or flashlight. However, if you don’t have any of these, you can use your phone LED flash,
  • Cellophane: You can color transparent pieces of cellophane using a market, or buy specific cellophane that is purple and blue.
  • Marker: If you are going with transparent pieces, you will need a purple and blue marker to color them.
  • Scissors: You’ll need scissors to remove any extra tape.
  • Rubber Bands: To hold cellophane in place, you may need rubber bands initially, before taping.
  • Tape: Use sellotape to hold the cellophane in place.
  • A Testing Device: After making your black light, you will need something to test. You can use a black poster, however, white paper or highlighter also works fine.

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How to make a Black Light out of a Bulb, Flashlight, or Smartphone?

Step 1: Take your light source; phone, flashlight, or light bulb.

Step 2: Color your cellophane (if needed).

Step 3: Cut the cellophane to the size of your light source. Remember, you have to cover the light source so that no light can pass through it.

Step 4: Apply the pieces of cellophane and secure them. Use the following order:

  1. Blue
  2. Blue
  3. Purple

For flashlight users, it’s easy to apply the pieces and secure them with rubber bands. In case you’re making a black light with your phone, use tape to secure the cellophane to the light source.

Step 5: Now it is time to test your black light. You can test it out on a black poster, or take plain paper and paint it black. For extraordinary results, you can put some highlighter or fluorescent liquid on it.

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Benefits of a Black Light

1. Medical Equipment:

Hospitals use black lights or UV rays to sanitize equipment and inspect germs in operation theaters prior to surgery.  

2. Germs Inspection In Food:

Food companies often use black lights while packing products. Its exposed rays can easily detect invisible germs that can cause bacteria or spoil food.

3. Black Light as a Bug Detector:

It’s always useful to use black lights to clean an area from pests that sting or bite, like mosquitos. Black lights can be useful when camping.

4. Authentication

Banks and retail stores have been using black lights to check counterfeit cash for decades.

5. Research:

A scorpion’s body has fluorescent chemicals, which glow when exposed to ultraviolet rays. So, researchers can easily locate these creatures using black lights.

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Whether you have a specific reason for making a black light, or if you just want to see if your Star Wars FX lightsaber can become a black light (our goal), it is always good fun to learn how to do things.

However, excessive exposure to UV rays is known to cause permanent eye damage, such as macular degeneration and cataracts. So, if you’re a regular user, it’s recommended to use sunglasses.