Read on to find out what you need to pay attention to when laser engraving stone. Additionally, we will show you how to get amazing results every single time!
The best stones for laser engraving usually have very smooth surfaces or are polished stone slabs. For the best engraving results, the stone should have a flat surface. This will mean that the result is not distorted by curves or grooves.
You can even try your hand and laser engraving 'real' stones with rounded surfaces. All you'll need to do is place the stone on a horizontal plane. We suggest using a support for this, such as moulding clay. When focusing, use an average value of the area to be engraved. This will make the marking as uniform as possible.
Tips for purchasing small stones:
You can find most small stones - for things like jewellery, worry stones and runes - in the tile department of hardware stores. You can also find mosaic tiles, composed of small marble, multicoloured stones or even levelled river pebbles. You just need to detach the glue on the backside by placing the slate in warm, soapy water. This way, you'll get a variety of small, clean and inexpensive stones for laser processing in no time at all!
When laser engraving stones, you will inevitably produce a considerable amount of dust. This can stick to your material and cause damage, depending on the type of stones you are using. Always ensure that you check your nozzle prior to each engraving job - you can even check the nozzle during an engraving job if it's a long one. The nozzle can become clogged with dust and block the laser path, so by wiping it with a cloth or rinsing it under clean water, you can quickly and easily restore the laser to its optimal performance. The functionality of the lens and mirror should also be checked when laser engraving stone.
If you intend on removing the natural dust layer from your chosen stone, we suggest cleaning it before you begin laser engraving. If you rinse the stone in water after the engraving process, you may wash out a part of the engraving, potentially ruining your design.
Stones are a natural, organic material, and their geological composition will always differ. Here, we can show you how to achieve great engraving results for many kinds of stones quickly and easily.
Variant 1: The grayscale matrix
If you have a flat surface of at least 3 x 3cm, along with a sufficient test surface, we recommend applying the grayscale matrix. Unlike paper and wood, most hard stone surfaces will need full power and a low engraving speed. As a starting value, we recommend 100% power (p) and about 30% speed (v) for a laser power of 60 Wats, and 15% speed for anything less than 60 Watts. If this setting is not giving you the right results, reduce the speed and run the matrix again. The advantage of this method is that you are free to assign the exact power setting to every engravable field.
Variant 2: The grayscale gradient
This method is only efficient if the testing area is very limited. Draw a rectangle with a gradient from 100% black to white. The same printer driver and parameter settings can be used, akin to the grayscale matrix method. The suitable power setting can only be determined with this method, so if it is in the middle of the engraved area, the determined power value will be 50%. The closer the black area, the more power you will have as a result for your chosen setting.
This method is great as it can be applied to very small areas.
The following is a list of engraving types that are, in our opinion, very well suited for laser engraving. The guiding values to achieve great engraving results were determined by us using a Speedy 360, 100 Watt machine. These ultimately depend on your laser power, your specific stone and your graphics:
- Marble: p50%, v20%, 1000dpi, Z = -0.5mm
- Slate: p20%, v100%, 500dpi
- Concrete blocks: p100%, v20%, 500dpi
- Pebble stones: p80%, v30%, 500dpi, Z = +2
- Basalt: p12%, v50%, 500dpi, Z = -1
- Agate: p50%, v30%, 1000dpi, Z = +1.5
- Bricks: p100%, v30%, 500dpi, Z = +1.5
Bright granite stones are only suitable for laser processing to a very limited degree - you will have to inlay their engraving with colour after the engraving process to get a high-contrast result. Below, we explain how this works:
Some stones will lead to no or poor results when laser engraved, and this is because of their geological composition. With these nifty tricks, you can still get useful results from your stones - no matter the type.
Change the Z-Offset Value
A change in the Z-offset value can significantly improve your engraving results in many cases. The most striking thing is to try offset values of +1mm, and then compare your results. For very hard stones, it may be better to choose a negative offset value. This will allow much more laser power to enter the engraving area.
Inlaying Your Engraving with Colour
Some stones will only ever yield poor results when laser engraved - unfortunately there is nothing you can do about this. However, filling your engraving with acrylic paint can sometimes improve these poor engravings. To do this, mask the surface that you will be engraving with application tape. Now, engrave your desired motif. Then, take some acrylic paint and a bristle brush and dab at the engraved areas with paint. once the paint has completely dried, you can peel away the tape and wash the stone with water. The smoother you polish the stone, the better the result will be. Porous or rough surfaces may cause the edges of your artwork to fray and appear fuzzy.
Contact us! Our laser experts are always happy to help.