A GUIDE TO LASER ENGRAVING -EVERYTHING YOU NEED TO KNOW

What is Laser Engraving?

Laser Engraving is a Subtractive Manufacturing method, that change the surface of an object with help of a laser beam.

This process is mostly used to create images on the material, that are visible at eye level.

For this the laser creates high heat that will vaporize the matter, thus exposing cavities that will form the final image.

How does Laser Engraving works?

• The high heat of the laser beam vaporizes the material, thereby cutting into the part’s surface and physically removing material.
• This process leaves a cavity in the surfaces that is not only visible with high contrast but also noticeable by touch.
• There are noteworthy differences in the depth of this cavity that varies between 0.02″ in metals to 0.125″ in softer materials.
• Usually, the engraved areas become black.
• Multi-layer materials offer an alternative, as they enable them to engrave other colors than black.
• By removing the top layers, the lower layers become visible.

What are the applications of laser engraving ?

• This process has become very popular for customizing parts made off metal, leather plastics, wood, glass, and acrylic.
• In particular, it is a great tool to add numbers, logos, images, and serial numbers to parts.
• Laser engraving is usually used for producing promotional products like pens, signs, and displays.
• One of the most noticeable applications is engraved jewelry, like wedding rings.
• It can be used in various industries, such as medical devices, fine art and so on.
• It can be used for industrial applications, but it is also possible to get a DIY laser engraver machine, for example with a CO2 laser system.

How are Laser Engraving and Laser Etching different from each other?

• Laser Etching is a subdivision of Laser Engraving.
• In this particular case, the heat from the beam is not used to vaporize the matter, but to melt it.
• It is mostly worked on metals and expands the material by creating a raised cavity.
• It thus modifies its feature, such as its reflectivity, and creates a contrast with its surroundings.
• Compared to other processes using lasers Laser Engraving keeps the initial shape of the material.
• Logos, serial numbers, or pictures are typically the kind of creations that can be done thanks to Laser Engraving.
• One of the significant difference with Laser Engraving and Laser Etching is that here, the oxidation during the marking process make the material turn black. 

What are the file formats supported by Laser Engraving?

This Laser Engraving system DOES NOT work with 3D file formats, like. stl.

The model will then be converted into dots, and the distance between two of these dots will determine the depth of the engraving.

Then the 2D model will be sent to an engraver machine.

The machines used for Laser Engraving are the same that are used for Laser Cutting.

What are the materials used for Laser Engraving?

To choose the optimal laser engraving settings, always test the engraving machine with a grayscale matrix as different materials behave differently: –

Get Instant 3D Printing Quotes + 10% Off

Upload your model, compare prices instantly, and unlock 10% off in seconds.

In-house capabilities: SLA • SLS • MJF • FDM • DLP

Compare Prices & Get 10% Off

OR

Talk to an Engineer (Free)

Served 10,000 Customers Worldwide • 75+ Dedicated Staff • Supports STL/STEP

1.  Laser Engraving Leather

• Finished Leather can be engraved for a perfect branding look.
• Try to minimize work on raster marking large surfaces, as the leather will turn powdery.
• Hence, vector marking is recommended.
• As leather is a natural material, it may sometimes deform during laser engraving if too much power is applied.
• Leather has many types and so it is difficult to come up with a general rule for laser engraving.

2.  Laser Engraving Wood

• Besides natural woods, there is also plywood, which has several properties that makes it fit for laser engraving.
• It consists of several sheets of wood that are glued together. As a result, plywood increases mechanical resistance, water-resistance, and lightness.
• All these properties have made plywood a perfect choice for builders, designers, artists, and craftsmen.
• When cut into sheets, the latter reveals grains in alternating shades that stem from different kinds of growth during the seasons.
• These differences also transform 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 zebra pattern, you will be better off using plywood that has a uniform surface.
• Besides, you should always apply higher laser power when engraving hardwood. Only then will your smooth results.

3.  Laser Engraving Glass

• The effects the laser has onto the glass surface can be changed 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 applies.
• However, the final engraving colour is not a bright white but looks grey.
• Once the engraving is finished, the tape residue can be removed off easily.
• When your laser engraver has not enough power to engrave glass, even then, you can achieve designs with high-contrasts just by masking 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

4.  Laser Engraving Stone

• Using Polished stone for laser engraving gives amazing results.
• Distortions of the laser engraving motif, can be avoided by use stones that have a flat surface.
• Natural stones can be aligned with the laser by using modelling clay as support.
• When you set the laser’s focus, apply an average value to achieve a uniform result
• If your results are unsatisfactory, consider changing the Z-offset value.
• This simple trick can significantly improve the result of your engraving.
• Many professional laser engravers experience 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 is simple. The closer the surface to be engraved is to the laser, the more energy enters.

4 Things to remember while Laser Engraving: –

1.  Calibrate your Laser

• We suggest that you test 10 to 15 increments of 1mm in the Z-axis.
• Prepare a series of files that contain a straight line and the value you are testing.
• Once your series of tests is complete, compare the results.
• You want the laser engraving with the thinnest solid line.
• Use this value for your future laser engravings.
• The same applies to test the intensity of colours.
• The advanced laser engraving machines can achieve a broad spectrum of shades.
• However, the appearance of the final engraving cannot always be deduced by looking at the raster file.
• By laser engraving, a grayscale matrix onto the desired material is an easy way to achieve predictable results, as you can “read” the intensity of shades on a scale from 0 (white) to 100 (black).
• Ideally, you should run this test for every material you want to laser engrave for the best possible results.

2.  Avoid Smoke Stains

• Laser engraving on materials such as wood and leather, can sometimes stain the surface surrounding the engraved area.
• While some makers like this “branded” look, it can be easily avoided.
• Protect the surface of the part using masking tape.
• The tape is so thin that it will not diminish the power of the laser much.
• If you feel that may be an issue, increase the laser power a few notches.
• After the laser engraver is done, peel the masking tape off your part.

3.  Keep your Laser Engraver Clean

• Tidiness at the workplace should be a no-brainer.
• However, concerning laser engraving, we’re not merely talking about courtesy towards your co-workers.
• Materials like wood, plastics, or rubber leave large amounts of dust that may cause unwanted results like discolorations, burnt debris, or even distortions.
  Install an exhaust system that has the necessary capacities.
• This will take a lot of weight on your shoulders.
• However, it will not clean the entire machine, so you should clean the laser engraving regularly by hand.
• You can remove most of the dust with a simply kitchen-cloth.
  You should also pay extra attention to the machine head and the laser lens.
• These components should be free from dust and smut at all times to avoid laser engraving mistakes.
  In case your part is smaller than the work platform, cover the rest with paper.
• This simple trick will increase the efficiency of your exhaust system and save you a lot of manual cleaning.

4.  Use Templates to Engrave Multiple Parts in One Session

• Templates are a safe and cost-effective way to laser engrave multiple parts in one process.
• They fasten the objects into fixed positions that are known to you and your laser engraving software.
• Hence, you are not bound to laser engrave objects one by one, but instead, you can process entire trays in one session.
• Watch out for the volume of your workpieces.
• For thin objects, flat templates are sufficient to keep them in place.
• In case you work with a large number of different templates, make sure to write (or better laser engrave) the name of the graphics file in question on to the template.
• This will make it so much easier to match your tools in your daily work.
• File small templates in folders to keep them safe and organized.

What is Relief engraving?

• It is a variant of laser engraving.
• In this method, Laser creates deep engraving with different heights.
• This variant is the most impressive since the overall effect is that of a wooden sculpture.
• When creating relief engraving, you need a grayscale design and set your laser to translate the different values into different heights.
• This method is fast, as the material is removed with each pulse of the laser.
• The depth of the marks is controlled by the number of times the laser beam is passing on the material.