I posted these engraved glass bottles in Made on a Glowforge and was asked for the settings I used.
I used a speed of 500 and a power of 70. When engraving on a curved surface, I also set the material height to be a bit lower that the actual tallest part of of the surface…my thinking is that it will help the laser focus a bit better across the overall surface, especially the surface area that’s a bit lower. Not sure if that’s really needed, but I thought I’d mention it.
edz
Wonderful outcome!
Looks like your settings are spot on. 
Nice. What is the diameter of the glass bottles?
The clear glass jar is 1.7 inches and the brown bottle is 1.48 inches in diameter.
edz
Thanks!
Appreciate you taking the time to post your settings. Thank you.
Another bottle engraving. This time, a larger bottle. The bottle diameter was 2.33 inches. Note that the laser was unable to etch near the apex, but was able to engrave slightly lower, definitely above 2". There was distortion of the original image though due to the curve of the surface.
Thanks for posting your findings, I certainly appreciate it. Glass bottles are somewhere on my what to burn list…
This is where I wish again for the ability to lower the bed floor. I see that the Rockler now has a laser (Laguna PL 12/20) in their catalog that has a bottom that can be removed. I don’t want to think about the laser safety issues there. I would like to have a worm screw adjustable bottom though.
Yeah, that would be nice, but there’s always going to be some limit. To be honest, I’m still just thrilled I have a laser cutter at home 
edz
It’s been done Cutting Out the Bottom of Your Glowforge . It feels a little extreme to me, but …
I saw that, but I’m not willing to hack my finely-tuned machine. 
