THERE ARE BETTER WAYS TO DO THIS (probably).
Dry erase ink:
Whats in Dry erase pens an dink:
I've had a NEJE 1000MW laser printer for a while now. You can get them for about 70$ from lots of places.
I always wondered why they send you a little dry magic marker with the laser, here's why...
The pigment in Dry magic markers will thermally bind (weld) to the surface of plastic, as its being engraved. This means you can effectively "print" in colors using different dry erase markers using the NEJE 1000 MW laser.
The reason that I use this method is for engraving labels on inserts for 3D printed objects.
Here how (pretty simple). Dry magic markers or Dry erase markers come in lots of colors and wash off a shiny plastic surface using water. If you put some on a plastic surface and engrave over it, the laser welds the pigment from the marker to the plastic and the rest washes off, the welded-in pigment its then permanent.
You can use lots of different colors like blue, black, purple, green etc. You can even combine colors on a single laser engraved surface. Black does best at a speed setting of about 10 and other colors do fine at about 20. Experiment with the kinds of thermo-plastic that you want to use.
I used an opaque white milk bottle (shiny side) for this demonstration.
Yes this technique works with lots of different lasers...
I called the company and asked why they put a dry magic marker in with the NEJE 1000MW laser. The tech support at NEJE got the question from the sales team at GearBest.
After you laser engrave onto the dry erase covered surface.
Wash the non-engraved surfaces off with water.
If it stays on, with even hard rubbing, then its thermally bound, if not then increase the speed setting (paradoxically that means the laser spends more time on each dot), until it melts the pigment from the marker into the plastic without burning it.
BTW, you should really read and do all the safety stuff.
I'm not telling you what to do here, just sharing what I've tried.