Good morning/afternoon/evening,

I am working on a project in my spare time, and was wondering how this effect is created. enter image description here

and enter image description here

I am going to assume this is more than just a cutout with an LED behind it, but if I wanted to do a simple LED indicator, not shapes, how would that be done? My initial guess is that a piece of black translucent polycarbonate with an LED behind it would do the trick. Would this produce a nice little circle?

Thank you!


2 Answers 2


On first inspection this looks to be done with diffuser placed above an LED light source. That will expand the cone of light generated by the LED to cover a larger area. As for the shape, it looks to be clear polycarbonate or acrylic that is painted on the inside with the image cutout.

There are other ways to do this, but if you're working on something for simple hobbyist level development this is by far the most practical. Large scale operations may embed the image shape into the plastic. That will last longer but is more difficult and expensive to do

  • $\begingroup$ You can actually get acryllic sheets that are meant for engraving (w laser) that is black on top then after you engrave it to a certain depth its white, and if you engrave more its transparent. and its used in exactly these kinds of things. $\endgroup$
    – joojaa
    Jul 29, 2017 at 9:07

that's probably just a milky plastic sheet called a led diffuser.

The led has a directionality, which spreads light over an angle by distance, it can be guided with optical guides, mirrors, reflectors. grooved notched transparent sheets than deflect light into an acrylic plate, and then diffused using a led diffuser.



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