Mastering the Art of Glass Engraving with Lasers

When it comes to engraving transparent materials like glass, there are certain unique challenges to overcome. This difficulty primarily stems from the nature of diode laser engravers which emit light in the visible spectrum. Essentially, any material that appears transparent or light-colored to our eyes will not absorb this laser light, resulting in no change to the surface.

By contrast, CO2 lasers operate within the infrared spectrum. In simpler terms, the laser light they produce is essentially just heat, which gets absorbed by nearly all materials. However, the downside is that CO2 lasers are significantly larger and more costly compared to their diode counterparts.

But don’t despair! There’s a handy workaround to this transparency conundrum. By coating the glass surface with inexpensive black spray paint, watercolors, or even using a black permanent marker, we create a dark surface for the laser light to work upon. Post-engraving, this paint can easily be removed using acetone, revealing your beautiful design.

The finished product?

An engraving that bears a striking resemblance to a sandblasted surface. This effect is achieved by the laser creating minuscule cracks on the surface, resulting in a texture that’s not only permanent but also impervious to brushing off.

To give you a head start, here are the settings we’ve found effective for engraving glass:

• Fill+Line engraving
• Crosshatch infill, at a speed of 500mm/min and 100% power
• Line after fill (or the outline of the letters) at a speed of 300mm/min and 100% power

However, remember that these settings are not one-size-fits-all. You’ll need to experiment and make adjustments based on the results you’re getting. Always aim for that perfect balance between power, speed, and the desired outcome.

FAQ

1. Why is glass engraving challenging with lasers? Glass is a transparent material that doesn’t absorb visible laser light from diode laser engravers, which makes it difficult to etch.

2. How do CO2 lasers differ from diode laser engravers? CO2 lasers emit light in the infrared spectrum, producing heat that’s absorbed by nearly all materials. However, they’re bulkier and pricier than diode lasers.

3. How can I overcome the problem of glass transparency when engraving? One solution is to paint the glass black using cheap spray paint, watercolors, or a permanent marker. This gives the laser light a dark surface to work on.

4. How does the laser engraving surface look and feel? The laser creates tiny cracks on the glass surface, resulting in a rough, permanent texture similar to a sandblasted surface.

5. What settings should I use for laser engraving glass? While settings can vary, a good starting point is Fill+Line engraving with crosshatch infill at 500mm/min and 100% power, and line after fill at 300mm/min and 100% power. Adjust as needed based on your results.

Happy engraving!