Made this for a friend using my 7W JTech laser on the Shapeoko. He’s a very big dude and his nickname is “Squatch”.
The key for lasering glass is to find a relatively flat bottle because round bottles cause the laser to go out of focus on the curves.
Any special prep or post processing? That looks nice! What settings did you use, power and feed rate?
After much experimenting…100% Power, 10 inches/minute. (Glass is transparent to diode lasers like the JTech, so you have to mask it with something.) I tried blue tape, regular masking tape, sharpie and several types of paint. Blue tape only works with solid black text, not with a dithered image like I’m using. Regular masking tape and sharpie are useless. Flat black spray paint works the best with a dithered image. Mask everything carefully, spray the paint, wait 15 minutes and laser away. Then clean up the paint with lacquer thinner.
Nice job! +1
I’ve got one of those people around me that just get teased a lot. 
I did a few tests when I got my Jtech laser, but not on glass. What I found was since they put in the “high res” lens, I have almost 1/2" of relatively spot on focus. That does tend to “straighten” the curve on a bottle. I’m going to test on glass.
Also, I found that white Rustoleum paint works very good on most stuff. I think the white has more of the metal in it (for brightness) than other colors. I’ve use that on ceramic tiles. I only wait about 20 minutes before burning with the laser.
I tried white Rustoleum spray paint on glass. It works, but it results in a black image instead of frosted, which is no bueno for amber-colored whiskey. It would be OK for vodka or clear tequila, but white-frosted letters (from black paint) look better with whiskey. White paint makes nice black letters on white ceramic tile. I think it’s from the titanium dioxide they use in the white paint.
I tested on a round bottle. I too have the “high res” lens, but the burn faded to nothing pretty quick as it started to curve away. Glass seems to need a lot of energy. 100% at 10 ipm would cremate wood.
