Buenzli/Demodays OHP (overhead projetor) competition has many of those

https://www.youtube.com/watch?v=6G5rTavyx7A

https://www.youtube.com/watch?v=AZ39obFzaQs

https://www.youtube.com/watch?v=LCIsIfEOEI8

> Can you use a variable moire effect to create motion graphics?

Yes! https://www.creativebloq.com/animation/moire-effect-book-714...

This also reminds me of Lumii (now Fathom), which is an MIT media lab spin-out that prints multiple inkjet layers to create a 3D effect:

https://www.inkworldmagazine.com/contents/view_online-exclus...

Tons of interesting applications https://en.wikipedia.org/wiki/Moir%C3%A9_pattern#Implication...

I saw a good talk a couple decades ago where the speaker clued us into how with moire interference patterns, translation of one pattern turns into translational motion of the interference pattern that is 90 degrees offset (e.g., move one grating to the left/right, and the result moves up & down), and a rotation of one grating against another becomes scaling of the resulting pattern. He had lots of neat examples of animation, hidden designs, magnification, moving text, morphing images, etc. I couldn’t find a link immediately, but he was working on a textbook explaining the theory of generalize Moiré patterns. With just a little searching, I do see lots of that kind of stuff describing mathematical and perceptual properties and various uses of Moiré effects.