Laser Marking FAQs

Laser marking, while a self-explanatory process by name, isn’t always as straightforward as one may think. With several types of marking and several types of laser that are able to leave a mark, we often find that many of our customers have questions about this useful process.

In the detailed answers below, we have laid out the most frequently asked questions that SPI Lasers receive relating to marking with lasers.

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What is laser marking?

This is the process of using a laser beam to leave a permanent mark on the surface of a material. The laser beam used heats up the surface layer of said material, which after oxidising, will permanently change colour. This mark is often black but can be coloured too. It can be used to mark various materials.

How is it different to laser engraving?

While both are similar in nature, and sometimes the terms are even used synonymously, they do have an important difference that isn’t always highlighted. Laser marking is the leaving of a permanent mark only on a material’s surface. Laser engraving, on the other hand, is the leaving of a permanent engraving in the material.

While laser marking oxidises the surface of the material that it is working with, engraving vaporises the area that it is targeting, permanently removing part of the material to leave the engraving. This engraving will, therefore, have a noticeable depth; a depth which can be controlled depending on how you use the laser beam.

Will the process damage my material?

No, but it will permanently change it. One of the biggest benefits of using a laser, however, is the fact that it will only change the area that it is working with as it is a non-contact process and very precise too. This allows you to leave a mark in only the area you target, and not affect the area surrounding it.

Alongside this, no material is actually removed during the process. Instead, it simply changes colour through heat and oxidisation.


What is annealing?

Annealing is a type of laser marking, used only for metals. Through the oxidisation process, the mark that is left will be of colour, rather than black. The resulting colour will change depending on the level of heat that has been applied.

What is colour marking?

Similar to annealing (and sometimes called staining), this process will leave a coloured mark on a material. The difference here is that it will be different colour shades.

What is removing?

The removing process will leave a permanent engraving in a material, and so for that reason it is perhaps more closely aligned to laser engraving, but we thought it would be worth touching on here too.

Here, an engraving is made into the top coating of a substrate. This will leave a noticeable contrast between the engraving and the remaining top coat that surrounds this engraving.

What is foaming?

With foaming, gas bubbles are produced following the interaction of the laser with the material. These gas bubbles reflect light, and so the marked area that remains will be lighter than the surrounding areas which haven’t been targeted.

What is carbonising?

Carbonising works in a similar way to foaming, except the opposite result is produced. The area that is targeted will be darker than the areas around that haven’t been laser marked.

What is night and day marking?

Night and day marking is used to leave a permanent mark that is easily readable in both the light and the dark as it can be illuminated. This type of marking will be used on places such as car dashboards.

What materials can be laser marked?

A variety of materials can be laser marked, such as:

  • Brick
  • Titanium
  • Copper
  • Cast iron
  • Plastic
  • Steel and
  • Ceramics

What are some typical applications for this method?

Considering the various types of laser marking that can be completed, the various materials that it can work with, this handy process is used in many ways. Its most common usage is for identification markings on products, such as barcodes or QR codes. It is also used in this way to add dates to products too, such as use by dates.

The laser marking process can be used for the creation of ID cards

The laser marking process can be used for the creation of ID cards

Another popular use for the process is with the creating of things such as ID cards. Laser marking offers extremely high levels of fraud prevention.

It is also used for commercial and aesthetic reasons too, such as for the enhancing of jewellery products.

What industries is this process used in?

Given the wide range of materials that can be laser marked and the many applications that it can complete, it enjoys usage in many industries. This includes:

What types of laser can be used for marking?

The three most commonly types of laser used are gas lasers, crystal lasers and fiber lasers. Here at SPI Lasers, we only manufacture fiber lasers. We believe that they offer the largest array of benefits over the other alternatives on the market.

If you are looking for a good recommendation, then our redENERGY® G4 Pulsed Fiber Laser is the perfect choice.

What are the benefits of laser marking?

With laser marking and fiber lasers, you are offered many benefits. This includes total control of the beam wavelength and intensity. This allows you precise control over the final mark that is delivered, and as it is a non-contact process, won’t affect the surrounding areas.

It will also leave a very high-quality, permanent mark that will be easily readable and identifiable for whatever purpose you need it for.

Can’t find what you’re looking for?

Above are just some of the questions that we receive, but we often get asked some questions less frequently, and we can’t fit everything onto one page! If you have a question and you can’t find the answer listed on this page, please don’t hesitate to reach out to us here.


Image credits: TeroVesalainen, moritz320 and Dom J


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