Laser engravers are great for cutting solid and flat surfaces. Hence, many carvers use this machine to engrave their designs with finesse.
One of the most popular flat surfaces for engraving is glass, of course. You can see engraved designs on glasses, mirrors, windows, coasters, and a wide range of other accessories.
However, there are many types of glass. Some are pretty easy to cut and engrave, but tempered glass is another kettle of fish.
Can you laser-engrave it? Yes, you can. But it is a much more complicated process.
So let’s start from the beginning.
Difference Between Etching and Engraving
As you probably know, there are several types of carving. You can cut, etch, or engrave your material to form different shapes and curves.
When you’re cutting firm elements such as wood or metal, you may not notice the difference. You’ll focus on working as precisely as you can.
However, when you work with fragile objects such as glass, there’s a significant difference. For example, everyone knows that you can laser cut glass along the edges effortlessly.
But there’s a small yet essential distinction between laser etching and engraving.
When you engrave, you cut out a considerable chunk of the material to create a design. It cuts deeply into the material, leaving a visible cavity in the shape of your image.
Etching will just scratch the surface of the material; hence it resembles a drawing more than a cut. It effectively only removes the thin top layer of the glass. It requires far less power and speed.
Therefore, laser etching feels more like a “drawing on the glass” because it’s smooth to the touch. On the flip side, laser engraving is significantly deeper, and you can feel it under your fingers more easily.
Also, the etching process usually requires the addition of ink and certain chemicals to form a visible, durable picture.
Can You Laser Engrave Tempered Glass?
Put simply – yes, you can laser engrave tempered glass. The problem is in the outcome.
Tempered glass already went through a heating process, which makes the outer surface stronger. However, that heightens the tension in the inner layers, making them vulnerable.
Following that logic, when the laser pierces deeply into the tempered glass, there’s a massive risk of shattering. Even if it doesn’t break, it may still get permanently weaker and lose its primary purpose.
Many people like decorative coasters made of tempered glass. If they have deep engravings, exposure to hotter temperature (e.g., a cup of tea) could break it.
Some experts recommend carving your design before tempering the glass. Therefore, it will keep the shape and compress the outer surface to make it sturdier.
Here’s another tip: Your laser engraving machine is also your etching machine. That is, as long as you can adjust the power of the beam.
As a result, you’ll find countless examples of people laser “engraving” tempered glass when they’re actually etching. But if you like the final result, is the process even relevant?
The Best Way to Laser Engrave Tempered Glass
You should know that any type of CO2 laser engraver can cut through glass. However, it’s crucial to have a machine with an adjustable beam.
You may go through a trial and error period before you find the right intensity. However, you should avoid cutting deeper than 10% of the thickness of the glass.
Here are some tips that should help you during the engraving process.
Use a Damp Paper Towel
Laser is immensely hot, and high temperature weakens and breaks the glass. Put a wet paper towel over your piece before you start engraving for additional protection.
Use Lower Resolution
You should reduce DPI (dots per inch) when you cut through tempered glass. That leaves some necessary space between the dots to keep the glass durable. To keep the image crisp, use 300DPI. You won’t notice any difference.
Jarvis Dithering is a widespread carving process that you can use to enhance the look of your image. It adds the final touch by scrambling the dots. Your design will look smooth and high-quality without sharp edges.
If your carving has many details, you should set grayscale rasterization to at least 80% black. That will allow the machine to cut with less heat and with more detail.
Wear goggles, so you don’t expose your eyes to the laser. Also, look to shut any covers or cases on the devices to reduce the risk of exposure or reflection.
The Benefits of Glass Cutting
A laser is one of the best methods to cut most types of glass. Here’s why.
It’s Quick and Thorough
A laser can transfer all your designs with the utmost detail and precision. You can create some stunning shapes and cuts in a short amount of time.
If you’re looking to produce large quantities, laser engraving is the way to go. You can save the design and reproduce it as many times as you can with barely any difference.
It’s Relatively Cheap
Laser engraving machines are mostly affordable and long-lasting.
A laser engraver is appealing to designers, as it doesn’t require a lot of skill to operate.
They are Neat
Other carving processes may leave a lot of debris and dirt that you’ll need to clean afterward. On the other hand, a laser cutter leaves almost no traces and requires minimum maintenance and cleaning.
Engraving with Care
There’s a fine line between shattering tempered glass and successful engraving. Therefore, it may take some time to get the hang of it. It all depends on various factors, though the power of your machine and the depth of the cut are primary factors.
If you manage to find the right balance, you will be able to engrave various shapes with little trouble. On the other hand, you may also opt to etch tempered glass as it is significantly less risky.
Anyhow, getting things right will take some time and effort, so arm yourself with patience.