Hello @WedCylinder1769,
Yes, you are right. It’s as “simple” as that! Don’t forget to mirror your laser pattern, because it needs to be put at the back of your transparent plexiglass.
For the front plate, I’m using the same method. I used a white opaque plexiglass, paint it gray (RAL 7031), and then I’m again lasering the text/graphics. On my PCB, I’m using white LED’s to serve as backlighting. Because the plexiglass is opaque, the light is nicely spread. My panel is at about 5mm from my PCB, on which I put SMD LED’s at maximum distances of about 10mm from eachother to have a good equal light spread. As you can see in below PCB layout, there are a lot of LED’s (I have 59 backlighting LED’s).
To make my life easier, I’m using the SMT service of JLCPCB to put the LED’s already on the PCB, so I don’t have to do all that soldering myself.
The only disadvantage of this method is that in daylight without backlighting, the characters/graphics are very faint. I can live with that, because I intend to use my panels always with backlighting.
I once found a video on YouTube of somebody that created front panels with 2 colors (gray and white). He used a 0.2mm nozzle for high precision. He used a Bambu lab 3D printer if I remember well, which can handle multiple colors. I was really surprised with the result - although unexpected the characters looked perfect. And there, the advantage is that the white looked really white in daylight. I lost the video, but if I could get in touch with that person, I would like to ask him to do a test and print my panel (I would provide design and pay him of course). If the results would be as expected, I might buy a Bambu lab 3D printer as well, because doing it this way has a lot shorter workflow.
EDIT: I found the video back. https://youtu.be/WIdHBMIfGhQ?si=Yd6ikdlKWV-S_G1x