CO2 lasers are the most commonly used for engraving glass due to their ability to create detailed and frosted etchings. Diode lasers can also be used, but they often require additional steps like masking the glass with paint or cardstock for best results​ .

To prevent cracking, apply a damp paper towel or a thin layer of dish soap over the engraving area. This helps dissipate heat and protect the glass from thermal shock.

Optimal settings vary, but a common starting point for CO2 lasers is 20% power at 200 mm/s speed. For diode lasers, 100% power and 1500 mm/min speed can be used. It's essential to perform test runs to find the best settings for your specific laser and type of glass​.

Air assist is generally not required for engraving glass, but if used, it should be set to low pressure to avoid rapid cooling and potential fracturing of the glass​.

Yes, curved glass objects can be engraved using a rotary attachment, which helps maintain the correct focal distance as the glass rotates. However, this may require some adjustments to avoid issues with varying curvatures and potential contact with the laser lens.

After engraving, use a nail brush to remove any shards and rubbing alcohol to clean off residue. For colored engravings, a product like Rub-n-Buff can be applied to enhance the visibility of the design​.

A lower DPI (dots per inch) around 300 DPI is recommended for glass engraving. This helps create a better frosted effect by spacing the engraved dots apart​.

Proper focus is crucial to avoid flaking and chipping. For flat glass, set the laser focus to the surface in contact with any masking material used. For curved surfaces, ensure the laser maintains focus across the entire design by adjusting the depth of field​.

Almost any design can be laser engraved on glass, including images, text, logos, and intricate patterns. Design software compatible with your laser engraver can be used to create and adjust these designs before engraving​.

Yes, laser engraving on glass is permanent. The laser creates micro-cracks in the surface, producing a frosted effect that won't wash off or fade over time.