Why Are Horizontal Layer Lines Present on 3D Prints?

1. What’s Wrong with My 3D Print?

The printing issue is indicated by horizontal lines across the surface of your prints. We will get to know why this issue occurs and how we can resolve it in the later sections of this article.

2. What Causes the Printing Issue?

When a single layer fails to print properly, it forms a visible horizontal line on the 3D print. If this pattern repeats, more layer lines will appear. This issue gets mixed up with the layer shifting, pixel lines, or stepper lines issue, however, each issue has a different root cause.

Layer lines are usually caused by one of the following or a combination of the following reasons:

Resin profile settings

• Normal layer exposure time is incorrect
• Lift height is not high enough
• Rest time or light-off delay time is not long enough

Other settings

• Printer is paused mid print
• Supports are not strong enough
• Set up for hollowed prints is incorrect
• FEP film needs to be replaced

3. Troubleshooting the Printing Issue

Resolving this issue requires adjusting several settings as well as redialing your resin before adjusting the supports. The following steps are organized in order of likelihood to identify and resolve the printing issue:

Adjusting the resin profile settings

• Check out our Official Resin Profile and make sure you have dialled in the correct exposure time and sufficient lift height
• Make sure rest time is correct (for light-off delay time, please use this Auto Calculator)

Adjusting other settings

• Increase support density and upper diameter (for detailed suggestions, please refer to this article) 
• If models are hollow, make sure wall thickness should be at least 1.5 mm (2 mm for large models). Also, add at least 2 drain holes that are at least 3 mm wide to the bottom of the models
• Inspect the status of your Film and replace it if necessary

If you are using a third-party resin or cannot find your resin on our official resin profile page, please use a Resin Exposure Finder to dial in your settings. Light-off delay time is essential in resin 3D printing. With the correct settings, each layer will be printed in a much more stable manner, resulting in better quality 3D prints. Please refer to this article to learn more about Light-Off Delay.

Contact Support

By following the above suggestions, you can resolve the layer line issue. If you find any issues, feel free to reach out to Phrozen Support or your Authorized Reseller for further assistance. When contacting Phrozen Support, kindly send some photos or videos illustrating the issue.