Making or coding glass bottles for various consumer products is a frequent laser marking request that is achievable with CO2 lasers. UK-based Laser Lines offers a range of Synrad CO2 lasers for such applications. A request was made to the company to mark a small, 8-character alphanumeric date code on the outer rim of a glass nail polish bottle. A Synrad 10W laser and an FH Flyer marking head equipped with a 125mm focal length lens were used. This choice enabled a focused spot size of 180um on the glass surface, which was required to mark the small text size requested for the date code. This lens selection provides a 3mm depth of field that allowed the 8 characters to be marked in fine detail without exceeding the depth of focus. The resulting date code produced by these settings was completed in 0.34 seconds. The contrast produced by the mark is fairly low with a semi-transparent look: it does not detract from the overall "look" of the product but is still easily readable by the human eye.
