DIY Ultraviolet Light Indicator Strips

Make your own ultraviolet sensitive paper without any fancy tools or electronics!

You will need:

1. A suitable work surface (remember, Lumi inks will stain; that's the whole point of them)
2. A waterproof container, perhaps with a lid that you can put on halfway
3. Paper towels
4. One Lumi Inkodye Kit

Just the other day I purchased a set of PH indicator strips. They work well when you need to know the approximate PH of a liquid. There are more advanced ways to measure such a thing but these type of strips are easy to use and cheap. This got me to thinking if there was a similar product for detecting UV light, but I only found one commercial example online. Since I happened to have a Lumi Inkodye kit laying around, which reacts to ultraviolet light, I decided to make ultraviolet indicator strips. Here's how!

You want to make sure everything is ready before you start the process. Minimizing premature exposure to UV light is the key to a successful outcome. When you feel confident that you can perform these steps in less than one minute, proceed.

1. Lay out the paper towel on a surface that you do not mind staining permanently.
2. Pour a good amount of ink all over the paper towel and roll it around evenly. I used 1/4 of the bottle.
3. Carefully peel up the paper towel and lay it in your container loosely along with three or four dry paper towels.
4. Close the container loosely, allowing some air circulation and place it in a dark closet for a few days.

Once the dyed paper towel is dry, remove it from the container and cut it into strips as quickly as possible. Then, keep them in a dark place until you are ready to detect ultraviolet light with them. Upon exposure to UV light, the strips will turn color within a few minutes.

I created this Instructable because ultraviolet light intrigues me and I've wanted to do more projects involving it. I have a dozen or so UV LEDs laying around that I'd like to use in my next project so please + Follow and stay tuned! I also thought it would lend well to the Build My Lab Contest, so please Vote if you like it!