A resin print with a horizontal split is not automatically suffering from the same problem as a model whose upper half suddenly shifts sideways.
Delamination means cured layers are separating from one another. A print can also detach from its supports, warp around a large cross-section, lose individual layers, or experience a genuine mechanical layer shift.
Because those failures can look similar after the print is removed from the machine, diagnosis should begin with the shape of the failure rather than with random changes to exposure time.
First identify where the print failed, then change the smallest number of variables needed to test that hypothesis.
Identify the Failure Fingerprint
This distinction is not merely terminology. Formlabs defines delamination specifically as separation between cured layers, while its current Form 4 documentation describes layer shifting as layers being displaced relative to the build platform or previous layers.
Use the Raft and Supports as Evidence
Formlabs makes the same distinction in its troubleshooting documentation: a part separating internally while its raft remains attached is treated differently from a print that fails to adhere to the build platform.
Large Cross-Sections Can Create Large Separation Forces
Every cured layer must separate from the tank film before the next layer can be exposed. Geometry therefore affects the mechanical load applied during printing.
Formlabs identifies major changes in surface area between neighboring layers as one possible contributor to delamination. Its guidance recommends reorienting a part when necessary to reduce abrupt cross-sectional changes.
This matters when printing model-car bodies, chassis plates and broad flat components. A large roof or floor section positioned almost parallel to the build plate can create a very different separation load from the same part printed at an appropriate angle.
If the geometry repeatedly creates unnecessarily large layers, correcting orientation can be more effective than covering the model with additional supports.
Check for Cups in Hollow Models
Hollowing a large model can save resin and reduce solid cross-sectional area, but a poorly designed hollow part can introduce another failure mode: a cup.
A closed or poorly vented cavity can resist separation from the tank film. Formlabs specifically identifies suction cups as a potential contributor to delamination and layer-shifting problems.
For hollow resin car bodies or large components, inspect the sliced model layer by layer and make sure cavities are properly vented according to the printer and slicer workflow being used.
Drainage openings also need to remain functional rather than becoming trapped against the build orientation.
Supports Need to Survive the Hardest Layer, Not Just the First Layers
A model may print successfully for hours before reaching a cross-section that its supports cannot hold.
Prusa’s SLA troubleshooting documentation notes that prints can detach from their supports when the object’s weight and printing forces exceed what insufficient supports can handle.
When a failure begins at a predictable height, examine the sliced geometry at that exact layer.
| What changes near the failure? | What to inspect |
|---|---|
| Cross-sectional area suddenly increases | Orientation and separation forces. |
| A new section begins in mid-air | Missing islands or insufficient supports. |
| Hollow cavity closes into a cup | Drainage, venting and orientation. |
| Nothing unusual appears in the model | Tank, resin, optical system, platform and printer mechanics. |
Do Not Assume Exposure Is Always the Cause
Insufficient exposure can contribute to weak layers or supports on some systems, but exposure should be calibrated rather than increased indefinitely.
If several successful prints suddenly become delaminated without any profile change, inspect what changed elsewhere first: resin condition, temperature, tank film, debris, mechanical fastening or the model itself.
Extreme exposure changes can create different dimensional and surface-quality problems, so using extra exposure as a universal fix is poor troubleshooting practice.
Inspect the Tank After Every Significant Failure
A failed print can leave cured material in the vat. Starting another job without checking the tank can turn one failure into additional damage or another failed print.
Formlabs recommends checking the resin tank for cured debris and inspecting the film for damage or wear when troubleshooting delamination.
Follow the cleaning procedure for your exact printer. Filter contaminated resin when required and remove cured fragments before printing again.
When the Entire Upper Section Is Offset, Check Mechanics
A true lateral shift is different from a crack between layers.
Formlabs’ current Form 4 troubleshooting documentation lists a loose build-platform mounting system, platform misalignment, high separation forces and certain optical or release-surface issues among the possible causes of layer shifting on that printer family.
Prusa similarly documents skewed SLA prints caused by loose mechanical components on its SL1/SL1S systems, including platform and tank mounting points.
The specific hardware checks are manufacturer-dependent, so do not tighten or disassemble components based on instructions written for another printer model.
If an entire section physically moves relative to previous layers, include the platform, tank mounting and motion system in the diagnosis.
Large Solid Sections Can Warp Instead of Shift
Prusa notes that resin shrinkage during curing can produce forces that lead to warped or separated layers, particularly in large solid sections.
That can make a warped plate look like a registration problem even though no group of layers actually shifted sideways.
Where appropriate for the model, hollowing and changing orientation may reduce these stresses. Thin flat parts also require suitable orientation and support placement because distortion can continue during washing, drying or post-curing.
A Five-Print Troubleshooting Method
Before changing the entire profile
- Photograph the failed print before removing supports.
- Record the approximate layer or height where the defect begins.
- Inspect that location in the sliced file.
- Check the vat for cured fragments and film damage.
- Confirm the resin and temperature are appropriate for the profile.
- Check that platform and tank hardware are secured as specified by the manufacturer.
- Change one likely cause and run a controlled test.
- Record whether the defect moves, disappears or remains at the same height.
If the same defect appears at approximately the same place in the same model but other models print correctly, geometry or slicing becomes a stronger suspect.
If unrelated models begin showing similar shifts or separation, printer condition, tank condition, material or calibration deserves more attention.
Do Not Throw Away the Failed Print Too Quickly
A failed resin model is diagnostic evidence.
Before disposal, look at the direction of the split, where supports stopped, whether the failure corresponds to a large cross-section, and whether loose cured pieces were found in the vat.
That evidence can tell you more than simply knowing that the print “failed.”
Delamination separates layers. Support failure separates the model from its supports. Warping bends geometry. A genuine layer shift displaces later layers. Once you know which pattern you have, the number of plausible causes becomes much smaller.
Official technical references
The failure definitions and troubleshooting principles in this article were checked against current manufacturer documentation.
The LS Resin Lab Editorial Team publishes practical, detailed content about resin automotive models, scale-model painting, 3D-printing troubleshooting, surface finishing, airbrushing, and custom model-building techniques. Our guides are prepared for general educational purposes, with a focus on clear instructions, workshop safety, realistic results, and accessible information for hobbyists with different experience levels.
