Print Defects

Imperfect prints can be frustrating. Use the advice below to resolve issues with print defects. Make sure to share your own knowledge in the Formlabs Community Forum.

For prints that fail in progress, follow these steps:

  1. Hold the printer’s button for three seconds to cancel the print.
  2. Diagnose the failure with the guidelines below.
  3. Adjust your model or print settings.
  4. Clean your build platform and resin tank.
  5. Check and clean your mirror.
  6. Check the temperature of your printer
  7. Try your print again!

Frequently Reported Print Failures

Nothing Adheres to Build Platform

In this case, the base has partially or fully peeled away from the build platform. This is often a problem when your resin tank isn’t clean. If the resin tank is crystal clear, work with base thickness and the fine tuning feature to calibrate your build platform’s height. Be sure to:

part peeling off build platform
Part peeling off build platform

If you’ve had this problem while trying to print very small parts, you may have more success by trying another print location. Particularly, if printing in the middle of the build area, try moving to parts to the hinge side.

No Supports

Sometimes the base will print but the supports do not. When this happens the base may be too thin. Increase the base thickness under advanced support settings.

Part Separates From Supports

If the part was pulled from the supports, that usually means that the support tips were not strong enough. Try experimenting with the advanced support settings specifically by:

Part separating from supports
Part separating from supports
  • Increasing the touch-point size.
  • Increasing the density of supports.
  • If you are printing a larger part, it may be under-supported. You can add add manual supports, especially if the part is separating in one area.

Holes or Fractures

Several factors can cause holes or missing features:

  • A problem with your model mesh or orientation. Walk through the slicer in PreForm and if you see abnormalities (such as a hole or abnormal geometry), then go back into your 3D modeling program and check the mesh and how the faces of your geometry are joined.
Abnormal geometry in PreForm
  • Damaged resin tank: a cloudy or damaged resin tank can inhibit the laser and cause gaps in your print. Try printing on a different location of the build platform or replacing the resin tank.
  • Dirty optics: a dirty optical window or smudged/dusty mirror(s) can cause print defects. If your part prints with a clean uniformly circular hole through the entire model, that is usually caused by a piece of dust in the optical path.

If you’ve checked all of the above issues, try printing the part in a new orientation. Sometimes, hollowing the part may lead to better results.

Rashing and Ragging

Rashing occurs when your model comes out with a granular, bad surface finish. Ragging is more extreme and visually obvious, with the print exhibiting large or small flaps of material extruding from the sides of the model.

Rashing on printed part
Print with ragging on the surface

Both rashing and ragging are caused by dirt or dust in the optical path. If your model comes out with rashing or ragging, go through the following cleaning steps:

If you are still having printing problems, try using a new resin tank. Contact Customer Support if your prints come out with ragging even with the new tank.


Make sure to shake your resin before your pour it in the tank and mix before each print. A consistent chemical concentration is essential for quality prints.

Dimensional Inaccuracies

Several factors can cause dimensional inaccuracies:

  • Leaving your part in isopropyl alcohol too long. We recommend you shake your parts in IPA for 2 minutes, and leave to soak for 10 minutes. Especially for a part with fine features, the printed model can absorb the alcohol, causing it to swell and warp. Allow each print to dry fully before judging the final dimensions.
  • Your part might be inadequately supported, have very thin walls, or large flat areas that curl during shrinkage. Check your support settings and model orientation.
  • If your prints consistently come out skewed (i.e. mismatches in x and y dimensions, or orthogonally), your printer may require calibration. You can use the scaling feature or submit a support ticket for help.


Undercuring will cause your print to come out looking mushy because not enough laser power is getting to the part. Normally, this is caused by ghosting in the resin tank. To make sure your parts fully cure, use a new resin tank when you notice ghosting or cloudiness.

Explosions from Cupping

If you are printing a hollow object but have no drainage for it, it may “explode,” with a small failure propagating throughout the part. To ensure your hollow model prints successfully, change its orientation or add a hole for drainage.


If your model prints with the layers appearing to shift back and forth, check to see if your build platform is loose. If the build platform is secure and you are still having printing problems, contact Customer Support.

Stretching or Offset

When you model comes out skewed or offset on the build platform, run a test print and send photos along with a copy of your .form file to Customer Support.