13 Ideas for Diffusing LEDs

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About: Making and sharing are my two biggest passions! In total I've published hundreds of tutorials about everything from microcontrollers to knitting. I'm a New York City motorcyclist and unrepentant dog mom. My ...

This is a list of my favorite LED diffusion ideas, which I hope will provide you with some sparks of inspiration for creating your own next-level illumination. Examples and links are provided for each!

Step 1: Paper-Lined Shadow Box

We'll start out with an easy one: just start out with a box, either homemade or an easily found shadow box frame, for example, and line the inside with plain printer paper.

In my WiFi Weather Display project, for example, I broke the shadow box up into sections with a folded piece of corrugated cardboard. Then I taped some pixel strips to the back, shining into each triangle shape. In the Arduino code I control the color of each section of the pixel strand to create abstract weather patterns. Notice how the "snowy" status has some blue and some white LEDs, as compared to "rainy" with only blue.

The simplest form of this technique can also achieve a great result, and that's just to line the walls of the box with a single LED strip. Make the inside of the box white so the light can bounce around, and create a cutout face with the design of your choice. Learn more in my Instructable about this 2017 sign.

Step 2: Woven Fabric

Woven fabrics aren't stretchy, so they're easier to sew and keep flat. If you go shopping for fabric in person, bring a flashlight or use your phone's flashlight to test how different fabrics transmit light. Some, upon illumination, will show off an interior texture that you couldn't see from the surface. If you're shopping online, look for lightweight synthetic woven fabrics as a starting point. Faux flowers are also made of woven fabric.

If you're looking to smooth out letters on an LED scroller sign, the next obvious choice beyond paper is woven fabric. In the messenger bag display project pictured, I used solid white ripstop nylon to diffuse a large flexible NeoPixel display right up against the surface of the LEDs.

Step 3: Knit Fabric

Knit fabric is stretchy! Sweaters are knit, so are t-shirts. Knits can be tough to work with, but are great for diffusing LEDs! Like in the case of the pictured off-white fluffy cable-knit sweater: it diffuses the 8x8 NeoPixel matrix with an added texture that couldn't be imparted any other way. It's probably too thick to read numbers/letters through it, but the soft edges it gives the snowflakes are very festive.

The color changing scarf has an interior string of pixels diffused by a heavily gathered machine-knit panel. The folds of the gathered knit material were supposed to give a floral garland effect, but I think this thin grey yarn choice fell short of its goal.

Step 4: Plush Toys

Plush toys add a volume of fiber around an LED, usually synthetic fiber fill, and creating some volume can spread out the light and also highlight different parts of the toy. I created my first LED soft toy for a plush nightlight assignment in college (I made "irradiated" plush steak and the Chatter Pillow). Now I teach that same assignment as an exploration of materials in my classroom at SVA Products of Design.

2015

2016

2017

Step 5: Glass

Small mason jars often have an interesting texture, and can make a great base for a few different diffusion effects. Pictured is a simple 3D printed lid holding a single LED. Try filling the jar with translucent beads, or lining it with a simple piece of printer paper to pick up the glow. You can also paint the jar, inside or out. Learn more in my Instructable about making LED Mason Jar Lanterns.

Step 6: Backlit Laser-Cut Textile

You can layer fabrics for a wide variety of diffusion effects. This Sparkle Skirt project uses a laser-cut microsuede skirt as its base, and has the LED circuit sewn into the lining. When the LEDs light up, light bounces off the back of the overlay and the lining, creating a sophisticated backlight effect.

Step 7: LED Underlighting

You can use backlighting in many other applications as well. Technically it's not diffusion, since the light is reflecting off of something else, but we'll include it in our brainstorm anyway! In my Internet Valentine project, I glued tiny sequin LEDs to the back of a tissue paper heart, and they reflect off the white card behind to give the heart a red glow. Similarly, the red illuminated button shines up at the tissue paper heart on the remote to the left, bathing the layered pedals in red light.

Step 8: Laser-Cut Acrylic

Laser-cut acrylic affords a few diffusion opportunities, including edge-lighting, etching, and coloring in the etching with a marker. The photos here are from my Iron Man Arc Reactor project.

Step 9: Crinoline Tubing

I learned this tip from my pal Phil Burgess, who showed me this technique with his Cyber Falls Wig project. The crinoline tubing fits great over LED strip that's still inside its silicone sheathing, and catches the light with its cross-woven synthetic fibers. I used this idea in the Colorful LED Headpiece project pictured.

Step 10: Ping Pong Balls

Ping pong balls are a classic diffusion idea that is not used nearly enough, in my opinion. Cut a hole just big enough for your LED(s) (left) or cut them in half (right). Blast it with a cluster (like a NeoPixel Jewel, left) or use a single LED (right).

Or be like Moritz Waldemeyer and design a whole net costume with them!

I've heard that some safety trolls will say ping pong balls are flammable. So are many things on this list! Common LEDs and pixels will not get hot enough to light anything on fire, not even dryer lint. So ping pong naysayers, don't even start with me! =D

Step 11: Thermoplastic

Also underutilized in the maker scene, in my opinion, is thermoplastic for diffusing LEDs. This stuff comes in little beads you soak in hot water to make a pliable dough. It's not that easy to get precise shapes with it by hand, but I bet you could press it into little molds pretty easily. Anyway it looks great over powerful LEDs but the more that's on there, the less light will get through, since it's pretty opaque once it sets up.

Step 12: Adhesives / Glues

Different glues have different light transmission properties, and it's worthwhile to explore what magic you can make with the adhesives you already have access to. For this demonstration, I tried out hot glue, E6000, Lexel clear adhesive caulk, and a common household glue stick. You can build up multiple layers, or try whipping up the glues as they dry to create texture and tiny air bubbles. I was surprised to find that the tiny glob of hot glue on just the 5050 pixel package itself was durable and not easy to peel off. It gives a wide angle pleasant lens effect and might be my favorite result out of the whole testing process.

Step 13: 3D Printed LED Diffusers

There have been so many 3D printed LED diffusers in my life over the years, it seems unfair to group them into one idea, but dems the rules. Flexible white filament is my go-to, with a few notable exceptions like the LED coat buttons pictured (files).

These projects were all collaborations with Noe and Pedro Ruiz. Learn more at the tutorial for each:

Tiny TARDIS Pendant

Chameleon Scarf domed diffusers (file)

Bandolier of Light (file)

Unicorn Horn (files)

Cyberpunk Spikes (files)

Stego Spikes (files)

EEG Brain Cap Costume (files)

If you like this project, you may be interested in some of my others:

To keep up with what I'm working on, follow me on YouTube, Instagram, Twitter, Pinterest, and Snapchat.

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    23 Discussions

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    KellyCraig

    6 months ago

    I'm just starting to look to using LED's in a few projects they'd play well with. Of course, the more I play with them, the more facinating they become. For example, the effect of laying different colored plastics over different collored LED's quickly show the importance of pairing certain colors of LED's with certain colors of plastic or glass lenses.

    In the course of my very limited dabblings, I've noticed bright LED's still put off a lot of heat, which can compromise their longevity.

    Regarding the issue of heat, have you experimented with long term use projects that incorporated hot glue for diffusion, or that otherwise limit the ability of the LED's to shed heat and noticed a loss in dependability or longevity?

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    bill1959parkerKellyCraig

    Reply 6 months ago

    Hi Kelly I use ws2812 led strips off ebay for approx £16 for 5 Mtrs. That way each led can be a different colour if you want and if you buy a ws2812 led controller they are around £3 and a 5v plug in adaptor for £1.99 all from ebay china dont worry about it coming from china as any of these bought cheap in the uk will be from china you will pay 3 or 4 times more for same item from the UK also I have never had to pay duty on electronic items from china you normally get stung from USA for duty. If you use the ws2812 led strip just make sure you order everything 5V as 12V is available also but I like to stick to 5V as I sometimes program arduino's to run them and any boards like arduino raspbery pi and so on are all 5V. There is never any problem with heat. If you see Neopixel they can be used with the same controller as the ws2812.

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    KellyCraigbill1959parker

    Reply 6 months ago

    On Chinese purchases, I remodeled my kitchen a few years back and saved a small fortune ording light bars from other than U.S. sellers.

    When I wired the kitche (walls all still open), I jumped sinks and so on so all under-cabinet lights could be on one circuit.

    I wired the under-cabinet lights for halogens, since LED's were still expensive. As such, dimming would have been done via a 120 volt dimmer. LED's dropped and I gambled on a Chinese supplier purchase from LightingWill-dot-com.

    The lights were perfect, but I couldn't bury a xformer in the wall and dimming at the lights was not practical, but which I would have had to do using a standard power supply (rectifier). By switching to a magnetic transformer (much more expensive), I was able to dim through it, rather than via the output, allowing me to install dimable LED bars all around my counters (set back about 1-1/2" so the light hit the end of the counter).

    counter-1.JPGTile Done-1.jpg
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    bekathwiaKellyCraig

    Reply 6 months ago

    Nope, never experienced heat-related failure or loss of dependability from using any diffusion material, not ever. The copper traces on the PCB are functioning as heat sinks, and I've never had any of my projects become too hot to touch, either. (Can you tell I mainly make battery powered stuff and have never worked with 1W or bigger LEDs?)

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    bill1959parker

    6 months ago

    Hi Becky I stuck 36 ping pong balls onto a strip of ws2812 and put them in a large jar using clear silicone to stop them moving with all the strip and controller in the centre so nothing shows It had a tap outlet near the bottom I took that off to alow my power supply 5V cable to enter through the hole.. I made 2 one for my daughter and one for my carer and both love them. I used ir controllers off ebay but now after using BLYNK I wish i had used the ESP2866-12E so it they could be switched from anywhere. Thanks for the great idea of ping pong balls. I intend making myself one using cotton wool as i made an imitation fire with ws2812 and cotton wool and it looked vert effective. I am now following you and hope to try plenty of your ideas to pass my time and spend hours learning from you on my days of having to stay in bed due to my disability.
    Thank You

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    Jrock1981

    11 months ago

    I was wondering does anybody have nay ideas about going from a black color to light blue. i want to to a aqualad costume for Halloween. He has tattoos that become light blue from black as seen in the pictures.

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    telliston

    11 months ago

    Thank you for this instructable! I enjoyed reading it very much! I would be careful with flammable materials placed to close to any electronic parts ( this is about comments rather than your instructable). I used white plastic conduits and also polyethylene sprinkler pipes and they work great!

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    1 reply
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    bekathwiatelliston

    Reply 11 months ago

    This looks great, thank you so much for sharing!!

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    bekathwiaDonald Bell

    Reply 11 months ago

    Thanks for featuring my Instructable on Maker Project Lab, Donald!

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    Johenix

    11 months ago

    #14: White PETE bottles that things like "5 Hour Energy" come in.

    The neck ought to hold a 5MM LED- white or multi-color.

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    shamsrumi

    11 months ago

    I like all of your beautiful ideas for LED lights! thank you. I just posted my first instructable entitled flying machine. I love this website.

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    TechKiwiGadgets

    11 months ago

    Very cool nice work. Great ideas. Ive experimented with hot glue as a medium for LED diffusion on items which works well.

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    UncleEd

    11 months ago

    These are great! Thank you for accumulating them and writing them so we can share your ideas.

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    Matlek

    11 months ago

    Nice tips! When I use 5mm LEDs I also cut the tip of the epoxy case, so the light is not focused anymore.

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    SimonRob

    11 months ago

    It can be useful thank you !

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    plasmadischarge

    11 months ago

    Fantasitc Instructable! Thanks for posting this is really usefull for a few projects I was stuck on.