NEJE A40640 Not Etching Clear Acrylic – Only Removes Paint

Hi everyone,

I’m trying to laser-etch transparent extruded acrylic using my NEJE A40620 diode laser (blue laser, 450 nm). To make the surface absorb the laser, I painted it with red automotive spray paint. My settings were:

Power: 8%

Speed: 6000 mm/min

Passes: 2 (front and back sides)

The laser successfully removed the red paint, but it did not etch or mark the acrylic surface underneath on either side.

I understand that clear acrylic doesn’t absorb blue light well, but I was hoping the paint would help. After reading more, it seems red might reflect too much of the blue laser light.

My questions:
Should I use a different coating color, like black, to help with absorption?

Has anyone had success etching clear acrylic with a diode laser using a black film or paint?

Would switching to cast acrylic instead of extruded help improve the results?

Any recommended power/speed/pass settings for this laser on coated clear acrylic?

Appreciate any tips or examples from those who’ve made it work!

Thanks in advance.

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There’s a time to break out the CNC, and this might be it. I don’t think you’ll get any meaningful results with clear acrylic of any flavour.

Sorry for the complete lack of help!

I haven’t tried to etch clear acrylic with a blue laser.

That said, a couple of experiments you might try:

  • do a power test grid (like the one LightBurn makes, 8% power seems pretty low power for a diode)
  • Use a thin coating of titanium dioxide paint (bright white paint) with a bit more power. If this works, you’ll end up with black engraving of the material. It will be tough to apply the paint evenly.
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You’ll need a co2 laser for clear.

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thank you guys!
yes , i share you opinion.
but here the coating allowed the blue laser on acrylic, isnt it?

I have seen videos like this before and tried it my self. I was not able to achieve the same results as they were. I might could have gotten it with a LOT more trial and error. But acrylic isn’t cheap so I just use a Diamon Drag Bit on the LR4 and get what I need. Not as fast as a laser would be, but it works and its quite lol

Hi @Jonathjon !
I use the drag bit also, it works pretty well with vector, but not with bitmap(
My etching:

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That seems like a software issue. You could just convert it to svg using inkscape (easier said than done, but possible with most images you’d want to etch).

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Since he is wanting to use a bitmap image I assume he wants more than just black and white. He is wanting the gray tones as well, which the laser can do. The drag bit not so much. I could be completely wrong though.

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Yes , I would like to etch the photos