Why is My Laser Leaving Lines? Everything You Need To Know

You may be asking why is my laser leaving lines? Laser engraving is a popular method for adding designs to various materials. You can create beautiful, intricate designs with laser engraving. However, problems may occur, like leaving lines, and you wonder why this happens.

This could be caused by the laser beam moving back and forth over the surface, removing material in an uneven pattern. Lines can also be left behind depending on the speed at which the laser is traveling. It could also be because of contamination on the surface being engraved.

In this post, I’ll take a look at some of the potential causes of this problem and offer some solutions. So, if you’re troubleshooting why your laser is leaving lines, read on.

Why is My Laser Leaving Lines

Causes of Laser Leaving Lines

Read on for a detailed discussion of some of the potential causes for laser leaving lines:

Unstable or Weak Laser Beam

The laser beam can be weakened or destabilized due to misalignment of the components in the system, such as lenses and mirrors. It can also be due to poor maintenance resulting in an uneven pattern being created as it moves across the engraved surface.

This will further cause it to be unable to remove the material consistently, resulting in lines being left behind.

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Improper Focus of Laser Beam

Focus of Laser Beam

It is important that the laser beam is focused correctly; otherwise, it will not be able to engrave the design accurately. If the laser beam is not focused correctly, it can cause uneven patterns or lines on the material being engraved – especially when it is a curved surface.

Check if the focal length is correct, especially after the lens is cleaned or replaced. Pay attention to the direction of the focusing lens. Adjust the correct installation direction and focal length of the focusing lens.

High Engraving Speed

The laser traveling too fast over the surface can cause residue material to be burned and melted instead of vaporized. This will leave an uneven pattern on the surface that can look like lines.

Low Engraving Speed

When the engraving speed is too slow, the material may not be properly vaporized. This can lead to residue being left behind, which can look like lines.

Contamination on the Engraving Surface

If there is dust, dirt, or other contaminants on the surface being engraved, this could cause a decrease in quality and lines appearing in the engraving. It is crucial that you keep your working area clean to ensure the best results.

Laser Is Not Cutting All the Way Through

This could be due to the laser’s settings or a weak beam. If the laser is not cutting all the way through, it can cause a buildup of material on the surface which can also lead to lines or uneven patterns in the engraving.

Operator Error

Finally, operator error can cause lines to appear in laser engraving. If the settings are incorrect or the operator is not experienced with using the machine, this could result in uneven patterns being left behind on the material. For example, if you’re making multiple passes over the same area, then that could lead to lines.

Solutions to Fix Laser Leaving Lines

Now that we’ve looked at some of the potential causes of lasers leaving lines, let’s look at how you can fix this problem.

Check the Beam Alignment and Maintenance

The first step is to check your components’ alignment and ensure they are properly maintained. You can check your machine’s user manual to see the factory settings and adjust accordingly.

Check the Beam Alignment and Maintenance

Adjust the Speed and Power

If the speed is too slow or too fast, or the power is set too high or low, it can cause lines in the engraving. Different materials require different settings, so you may need to experiment with different speeds and powers until you find the right settings. Make sure to adjust these settings according to what’s best for your material and design.

Make Sure the Laser Is Cutting All the Way Through

The laser should be set to cut all the way through the material. If not, you may need to adjust the settings or use a more powerful laser for thicker materials. These materials are difficult to engrave, so ensure you don’t expect too much from your machine.

Clean the Engraving Surface

Before performing any engravings, ensure the surface is clean and free of dust or other contaminants that can cause lines. You can also use an adhesive spray or tape before engraving to ensure a stable surface.


Why are my laser-cut edges not straight?

If your laser-cut edges are not straight, it could be because the heat is more concentrated at the top than at the bottom. This can be due to the laser beam being misaligned or a lack of focus. It could also be because the laser speed is too slow, which causes residue material to remain on the surface.

How do I align my laser?

Aligning your laser is a necessary step before beginning any engraving process. You need to drive the laser head all the way to the back of the machine and press the ‘laser’ button to get a dot on the tape; take note of where this dot is.

Next, move the laser head toward the machine’s front and put a second dot on the target tape by moving the laser head toward the machine’s front. When the machine is aligned, the two dots should be in the same spot. If they are not, adjust the machine until they line up.

Can I engrave on any surface?

You can engrave on many surfaces, but some materials are better suited for laser engraving than others. It is important to research which materials your machine can accommodate and ensure the material is clean before beginning the process. You should also use caution as not all materials are safe for laser engraving.

Also Read: Best Materials for Laser Engraving

Final Thoughts

Laser engraving is a highly precise process that can produce high-quality results, but it is also prone to errors, such as lines appearing in the engraving. The causes of these lines range from misalignment of components to improper focus of the laser beam and operator error.

I hope this article has helped you understand the potential causes of lines appearing in laser engraving and what solutions you can use to fix them. Thanks for reading.