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Engraving black and white acrylic for illuminated letters



I’m currently evaluating options for creating a masking sheet that will go in front of some LEDs to create letter outlines. I wish to create something that has an opaque “background” but translucent white letters that will allow light to shine through.

I notice you guys stock a “black top white core” acrylic. I’m wondering if I could achieve my goal by having a sheet of that material laser-engraved so that the black top is removed and the white core is revealed below, and thus have the light shine through the engraved areas. I’d then place the material black-side-up, showing the white engraved letters on a black background.

Does that seem plausible or is there some constraint I’m not seeing that makes this a bad idea?

Also, given that I wish to engrave solid letters rather than outlines, am I correct to assume that raster engraving is what I need here?

Thanks in advance for your help!



You’re correct in that the raster engraving is what you would need to engrave solid letters (for reference, there is a summary of raster vs. vector engraving on the Capabilities and Limitations page of our Custom Laser Cutting Guide). However, the two-tone material that we stock has an opaque core layer that would not allow you to back-light your letters.

You might be able to find a similar two-tone material with a translucent core color available through Johnson’s Plastics that would work as you’re describing. You can order the material and have it sent to us for cutting/engraving, or we can special order it for you (a special ordering fee will apply).

If you prefer to use materials that we have in stock, you can still pull this off by using our translucent white acrylic and painting the “background” areas black. If you vector etch the outlines of your letters through the protective masking, you’ll be able to peel the masking from the areas you wish to paint, leaving the letters covered during the painting process (like a stencil). The larger the letters are, the easier it is to peel. Small/thin text is still doable, but you’ll want to be extra careful when unmasking so that the letters aren’t unmasked by mistake. Once the paint dries and you remove the remaining masking, you’ll have translucent white letters with a black background.

This painting method will likely be cheaper, since two-tone materials tend to be pretty pricey. If you have any further questions, please do not hesitate to contact us!

  • Arthur

P.S. In case this might be of interest to you, we posted a blog article about a laser-cut LED sign project here: https://www.pololu.com/blog/293/hopes-edge-led-banner.