What is the Difference Between Laser Etching and Engraving?

Is laser engraving the same as etching?

Many newcomers to the world of CO2 laser cutting are often confused about the terms “laser engraving machines” and “laser etching machines”. The general perception is that these machines are different — so do they differ? Well, to put you out of your misery, these machines are not physically different; the same laser engraving machine is used as an etching machine. The difference between engraving and etching is all about the depth of marking. With etching, the marking depth is kept shallow at about 0.001’’ to create vivid images. With engraving the marking depth is usually around 0.025’’-0.125’’ deep. So, it is safe to say etching is a subset of engraving, since the same machine is used for both processes. Now let’s briefly run through the art of laser etching and some useful hacks to successfully etch on popular materials such as glass and acrylic.

What is laser etching?

Laser etching is the process of making imprints on the surfaces of items and products of different materials by controlled melting of their surfaces. During laser etching, the laser beam provides a large quantity of energy to a tiny area to create a raised mark. As a result, the material's surface melts and expands resulting in a grey, white, or black colored marking on the material’s surface. Some permanent markings that are typically etched include photographs, logos, barcodes, serial numbers, and data matrix codes. You can see that etching is best for projects and designs that require high precision and near-perfect markings. 

What is the Difference Between Laser Etching and Engraving?

When you laser engrave, you are completely removing a section/layer of the material which leaves a cavity that the intended design is inscribed into. A high-heat laser is used to melt the material during laser engraving. And in tougher materials, engraving depths typically range from 0.02′′ to 0.125′′. For this reason, engraving is classified as a physical process. 

Laser etching, on the other hand, does not create a cavity in the material. Instead, it uses the medium laser power to remove only the top layer of the material. The removed layer is usually no more than 0.001”. For this reason, etching is classified as a chemical process.

Glass/Acrylic etching with an OMTech CO2 Laser Engraver is a seamless task, thanks to the efficient engraving speed, long-lasting laser tube up to 2000 hours, and ample working space. With an OMTech machine in your hands, simply lay your glass in the laser engraver bed (or the rotary attachment for cylindrical glasses) and then send the design from the computer to the laser to print. For your design software, consider LightBurn/RDWorks and make sure to punch in the correct settings for speed, power, number of passes, etc. as per your material and design. OMTech’s rotary attachment makes it simple to set up glass cups, mugs, vases, and wine bottles in a variety of different shapes and sizes. As the laser etches your cylindrical design, it will rotate the object.

Other benefits of using an OMTech CO2 laser engraver

• Affordability
• Dependable and Consistent
• Flexibility and ease of execution
• Speed and Precision
• Neatness

Hacks & Tips for Laser Etching Glass/Acrylic

As easy as the process of laser etching is, it could go south within the twinkle of an eye. To avoid this, it is necessary to sharpen your skill by learning some techniques while laser etching glass/acrylic. Here are some beneficial hacks for etching glass/acrylic using CO2 laser engravers:

Figuring out which type of glass/acrylic is best for laser etching

Before laser etching a product, the first thing to consider is the type of glass to employ. Crystal isn't suitable for laser engraving because it has high lead content. The lead will hold the heat from the laser, resulting in uneven engraving. The best types of glass to etch are those with low lead content. Cheap glass is a very good example of such.

Acrylic also comes in two forms; cast acrylic and extruded acrylic. And these two types are suitable for laser etching. While cast acrylic produces a frosted look, extruded acrylic is always clear and transparent. 

Using a low DPI

Using a lesser resolution while laser etching glass, such as 300 dots per inch (DPI) engraves the dots far apart. This results in a better finish on glass. You won't see that the image being engraved was produced at a lesser DPI, but it will result in a better outcome on the glass and prevent rough etched glass. In this case the same rule for glass applies to acrylic, after all, acrylic is called plexiglass sometimes. 

Optimum speed and power

Because flat glass has a uniform hardness throughout, engraved parts will not have light and dark patches. But bottles often contain soft and firm parts, the engraved part may appear softly frosted in one section and severely frosted in another. You should etch at medium speed with high power to compensate for differences in some glass.

For acrylic, you should etch at low power and high speed. Note that acrylic could be painted as well and in such a situation the laser power should be turned up by 10%.

Masking

Masking is not a compulsory step. Some people enjoy this tactic, while others avoid it entirely. Before engraving, mask the engraving area with a thin, damp sheet of newspaper or paper towel that is somewhat larger than the engraving area. This aids in the dissipation of heat, which can lead to chips or uneven glass surfaces. If the paper is not fully flat, the glass will not etch effectively.

Acrylics also require a paper mask from engraving suppliers for protecting other parts not intended to be etched clean and clear of burn marks. The paper mask from the acrylic manufacturer contains paraffin which is highly combustible. That's why you must remove and replace it with the one from engraving suppliers.

Which is Better Etching or Engraving?

While laser etching and engraving both utilize a scorching laser beam to melt away a layer of material, the best method to choose depends on your desired marking depth. 

Do you want to chip away a tiny amount to make a vivid, yet depthless marking?

Use etching.

Or do you want to chisel down to a significant engraving depth to create a deep contrast?

Go for engraving.

By now, I believe you should be convinced that CO2 laser engravers have a lot more tricks up their sleeve. Methods such as laser etching, marking, and cutting can all be applied depending on the material and settings used. OMTech offers the best CO2 laser engravers at decent prices for etching glass and acrylic, attending to various hobbyist and small business needs. OMTech’s laser machines are easy to use, but if you need any guidance, you can contact our support team or acquire professional training from our leading experts.  Do well to partner with OMTech on your next laser etching project to have a beamingly-endless experience!