Laser Engraving Stone

Laser engraved stone can have a stunning visual impact, especially laser engraving photos to granite.

Not all forms of stone will laser engrave so careful selection of the material is important. Stone is a general term that can be used to describe two distinct materials:

1. Naturally occurring stone, mined from the ground and shaped by breaking, sawing, cutting, grinding and polishing. Examples would be granite, marble or slate.
2. Man-made stones, also known as synthetic, composite or engineered stone such as alabaster, quartz and a range of trade names the most famous of which is Corian. These composites contain a blend of natural stone materials encapsulated by bonding resins such as acrylic. Composite materials are available in a wider range of finishes, more consistent in their make-up and are much easier to machine into shapes.

Each different type of stone will laser engrave with differing degrees of effect. Most natural materials will not vaporize. Laser engraving granite, for example, produces a result that is very similar to laser engraving glass where the highly polished surface fractures when pulsed by the laser with little to no depth.

Softer materials such as some types of marble and most of the composites will to a varying extent vaporise with some depth. This can be beneficial if, for example, it is desired to paint-fill the laser engraving to nhance the visual impact.

Materials that are dark in colour and more uniform in their make-up produce the best results. For example, some of the best effects that we have seen have been to carefully selected, black marble or granite that shows minimal flecks or veins in the material. If the stone has too much character this can irregularities in the mark and interfere with the image too.

Also important is the selection of the laser wavelength. For the majority of laser engraving to stone a CO2 laser at the 10.6µm is used. This type of laser is required especially when laser engraving composites with depth.

However, some materials such as slate, for example, can be marked with amazing detail using a fiber laser at the 1µm wavelength. This type of laser produces a focal point that can be x10 smaller than a CO2 laser and so the resolution can therefore be x10 higher.

Flatness of the material is important too, especially for stone that is Riven such as slate, for example. Too much variation in height will cause the laser to defocus and produce and undesirable result.

Last but not least, it’s important to note that stone is a very heavy material. With most machines there are limitations with regard to the weight of the material that can be loaded to the worktable. In such cases a workaround can be to use thinner stone tiles that after laser engraving can be mounted to a larger stone backing.

Some laser engraving machines exist that are specifically designed for use by monumental masons. These types of machine generally use a gantry mounted laser to move the laser over the stone. This type of machine is very limited in scope and is generally not well suited to a wider range of laser engraving applications.

At Lotus Laser Systems we manufacture a wide range laser, marking and engraving solutions ideally configured for laser cutting and laser engraving all types of materials. Our experts would be happy to recommend which configuration best suits your application.