Holographic Rainbow Reflective 3D Prints - 3D Printing on Diffraction Grating Sheets

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Introduction: Holographic Rainbow Reflective 3D Prints - 3D Printing on Diffraction Grating Sheets

About: Community Manager for Instructables and Tinkercad.

A few years ago, I learned you could 3D print on a diffraction grating sheet and it will transfer the rainbow reflectiveness onto the print (the same as this chocolate). Like most things, I tried it out, had some luck and some failure, then moved on to something else. Luckily, I decided to finally visit it again and am having consistent good results and wanted to share how I'm doing it, so you can too!

*Be aware that the reflectiveness works best in direct sunlight, but can also work with other lights.

Others who have shared about this previously:

Adafruit Industries

Benjamin Goldschmidt on All3DP

Instructable 362

Check out my shop on Etsy! You can also purchase these rainbow reflective earrings in my Etsy store.

Supplies

Step 1: Designing Your 3D Print

Now, you could probably do this with most prints, but my recommendations is to make sure your design has a nice flat surface (this rainbow effect won't go up curved sides, only the side that is touching the build plate), and the thicker the lines, the more rainbow reflectiveness you'll get!

I used a teardrop/raindrop shape that I imported and combined that with a Voronoi adjustable shape from the Shape Generators section of the shapes panel.



Step 2: Prep Your Printer

This is, obviously, the most important part for getting your rainbow prints.

In the past articles I had seen, others had either taped down the edges of the sheet or used a sticky sheet to completely convert a printer bed into a rainbow surface. The first option is what I tried and my prints constantly curled up, and the second I just wasn't ready to attempt. So I came up with an option in between that works great for me!

*I'm doing this on a spare spring steel sheet for my Prusa, but this is not permanent, so you should be able to do this and undo it whenever you need. It is meant to last, but not meant to last forever.

First, start by figuring out which side is rainbow (they aren't both rainbow).

Rub it between your fingers. One finger will catch and one will slide. The side the slides, should go up (I thought it would be the opposite but it isn't). If you print on the wrong side, your print will be shiny smooth but not rainbow reflective.

Now time to put the sheet down.

  • Start by cutting off a sheet of your diffraction grating roll.
  • I've only ever seen this stuff in 6" width so if you can find a bigger sheet, that's great.
  • Make sure your sheet isn't bent or wrinkled, it will wreck the finished result of the print.
  • Figure out what space it will cover (likely the middle) and put glue stick down on the build plate to cover the whole area the sheet will cover.
  • Carefully lay down the sheet and get as many bubbles out as you can.
  • I tried to use cardboard or a squeegee type object (these didn't work for me), but be careful about scraping the glue underneath the sheet through the diffraction grating sheet as that can also wreak the finish of the finished print.
  • Once it's all smoothed out, tape all edges down with blue painters tape.
  • Done!

It is very easy to take off the tape, carefully peel off the sheet, and wash both the sheet and the bed to get the glue off. I've done this a couple times already actually as the more you bend the sheet, the more it will start to pull up from the glue. I've reused the same diffraction grating sheet over and over too after carefully cleaning it.

Step 3: Check First Layer Height

My Prusa allows me to have settings for different sheets, so I did a different first layer setting for my "rainbow" sheet. It doesn't add much thickness, but it also doesn't hurt to get new settings to make sure that first layer works right. If you print too close, you could meld your print to the sheet, though this hasn't happened to me yet.

Step 4: Final Prints!

Have fun printing your designs!

I haven't noticed needing any special settings to get these to work right.

I tried it out with one of my floating mask designs too!

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    13 Comments

    0
    bpark1000
    bpark1000

    Tip 1 day ago on Step 4

    A scheme you may want to try: print conventionally, then prepare mixture of solvent & the plastic you printed. Make it good & thick. paint this on the surface you want the effect on, then press the diffraction sheet on & allow to dry for a good long time before you attempt to peel the diffraction sheet off. You may also be able to spray on clear lacquer & press the sheet on. You need a solvent that dissolves the printed plastic, but not the diffraction sheet.
    If you can get this to work, you can have diffraction effects on more than one surface, & maybe on cylindrically-curved surfaces. You could also use heat from behind the diffraction sheet, but there is a danger of melting the sheet. This would require careful control of the hot surface behind the diffraction sheet.

    0
    Alluviaal
    Alluviaal

    27 days ago

    This is awesome!

    Do you think I could also just use the plastic from a pair of paper diffraction glasses? I included a picture.

    Or alternatively, does anyone know a good EU/Netherlands source for the diffraction grating sheet?

    asdasd.jpg
    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 27 days ago

    Thanks!

    I'm just not sure. It's possible, but yeah I just can't say for sure.

    0
    NathanKing
    NathanKing

    4 weeks ago

    Thank you for sharing :)

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 27 days ago

    Thanks for checking it out!

    0
    nils2u
    nils2u

    4 weeks ago

    Diffraction gratings are great, so thank you for this cool project!
    They don‘t match my face, and I don’t have a printer (yet), so I won’t replicate it all too soon, but the idea is really great.
    Maybe you could simply use a bit of (olive) oil to provide a film, instead of an adhesive glue-stick? Heat-resistant - no bubbles - and the grating should stay put anyway when the sides are taped down => removal and cleaning should be easy. Just a question, as I have no experience.
    Have you tried old CDs on a laser-cutter? They provided pretty useful grids on some of my projects….
    I really like the idea of using a „mould“-sheet as template for multiple reuse.

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 4 weeks ago

    Thanks!

    I have not tried old CDs on a laser cutter. Like chris mentioned, you do have to be careful of the gasses that come off some materials when burned with a laser cutter.

    0
    chris.andersen.2700
    chris.andersen.2700

    Reply 4 weeks ago

    CD or DVD in lasercutter make dioxin and clor gas...

    0
    NirL
    NirL

    4 weeks ago

    This is amazing! I love it! I've never seen this type of use for a diffraction grating before! Thanks for sharing:)
    The diffraction sheets are not that cheap, how many times do you think they can be reused? Does it seem durable? Thanks! :)

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Best Answer 4 weeks ago

    Thanks!

    I have used them over and over again. I've even removed them from the board, washed off the glue, let it dry, and put it right back on. The main thing is to not tear, bend, or scratch it. As long as the surface is clean and smooth, you're good to reuse!

    It is a plastic film so I wouldn't necessarily say it's "durable" but it's not fragile like tissue paper.

    0
    NirL
    NirL

    Answer 4 weeks ago

    Thanks for the answer :) Your project is really inspiring, I already sent it to a bunch of people! Thanks for sharing!

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 4 weeks ago

    Even my daughter compliments them!