I’ve been using an 80w Rabbit laser (and it’s simply awful software!) at my local makerspace. My current strategy is to use hi-res 2-color bitmaps, matching the resolution in DPI (dots per inch) to that of the laser. In my case, the Rabbit says it’s good for 800 dpi, but 500-600 is much more realistic. Here’s an example I engraved at 300 dpi:
This image illustrates one of my biggest reasons for purchasing a GF. Notice that the image is aligned along the left side of the bamboo instead of centered. Despite my best efforts to calculate the center (and using the Rabbit’s boundary preview red laser) the actual cut was offset. I am eagerly awaiting my GF, so that I can have a live preview for alignment!
Btw, the scale is a bit hard to determine, but this is a $5 bamboo cutting board about 5x7 inches.
Here’s a link that includes the file I used as my source: