Laser engraving is so much more than fastening any material in the work area and pushing a button. Every material has its own quirks and idiosyncrasies that will sometimes help you achieve your design goal and sometimes make it hard on you. The following list will guide you through the properties of the most common materials.
Laser Engraving Leather
It is possible to laser engrave finished leather, producing a look similar to hot-branding. Avoid raster marking large surfaces, since the leather will turn powdery. Therefore, vector marking is recommended.
Since leather is a natural material, it may deform during laser engraving if too much power is applied.
Because of the many varieties of leather it is difficult to come up with a general rule for laser engraving it. Hence, there is no way around determining the optimal laser engraving settings for each kind separately. To this end test your machine with a grayscale matrix (see above).
Laser Engraving Paper / Cardboard
Because of the many varieties of paper and cardboard it is advisable to determine the optimal laser engraving settings for each kind separately. To this end test your machine with a grayscale matrix (see above).
Laser Engraving Wood
Besides natural woods there is also plywood, which has several advantages. This laser engraving material consists of several sheets of wood that are glued together. As a result, plywood boasts a raised mechanical resistance, water resistance and lightness. All these properties have made plywood a staple for builders, designers, artists, and craftsmen.
In terms of laser engraving, plywood has an additional advantage over natural wood. When cut into sheets, the latter reveals grains in alternating shades that stem from different kinds of growth during the seasons. These differences also translate into different laser engraved surfaces. Usually, the lighter areas will come out lighter and the dark areas will be darker.
As a rule of thumb, unless the desired look of your design is kind of zebra pattern, you will be better off using plywood that has a uniform surface.
In addition, you should always apply higher laser power when engraving hard wood. Only then will you smooth results.
To determine the optimal laser engraving settings, test your machine with a grayscale matrix (see above).
Laser Engraving Glass
The effects the laser has onto the glass surface can be manipulated using a number of practical methods.
Apply a moist paper towel to achieve a smoother surface finish and a white engraving result. Take care that there are no air bubbles or overlaps, because this would distort the effect. Once the engraving is finished the paper towel can be wiped off easily.
An alternative to paper towels is application tape. Like moist paper towels, application tape is an excellent measure against surface roughening. The same caveat concerning air bubbles and overlaps apply. However, the final engraving color is not a bright white, but looks grey. Once the engraving is finished the tape residue can be removed off easily.
But what to do when your laser engraver has not enough power to engrave glass? Even then you can achieve designs with high-contrasts! Simply mask the glass surface with tape. Then you engrave the design into the tape. Next, cover the revealed area of the tape with a thin layer of paint using a brush. After the paint has dried, peel the tape and remove the tape residue carefully.
Laser Engraving Stone
Experience shows that it can be piece of work to laser engrave stone. You will get the best results with polished stones. To avoid distortions of the laser engraving motif, try to use stones that have a flat surface. You can align natural stones with the laser by using modeling clay as a support. When you set the laser’s focus, apply an average value to achieve a uniform result
If your results are poor, consider changing the Z-offset value. This simple trick can significantly improve the result of your engraving. Many professional laser engravers report that hard stones are easier to process if you choose a negative Z-offset value of 1mm or even more. The physics behind this workaround are simple. The closer the surface to be engraved is to the laser, the more energy enters.
But what to do when your laser engraver has not enough power to engrave stone? Or, when working with extremely hard stones that yield no satisfying results? Even then you can achieve designs with high-contrasts! Simply mask the glass surface with tape. Then you engrave the design into the tape. Next, cover the revealed area of the tape with a thin layer of paint using a brush. After the paint has dried, peel the tape and remove the tape residue carefully from the stone’s surface.