How to Fix Warping in 3D Prints

Warping is when the corners or edges of a print curl up and away from the build plate. It happens because plastic shrinks as it cools. The bottom layers are held flat by the bed, the upper layers keep contracting, and the corners get pulled up. This guide lists the fixes in the order worth trying them. It is based on maker documentation, not our own print tests, so treat every setting as a starting point.

Why 3D prints warp

Prusa's knowledge base describes warping as mostly a problem with large objects and high-temperature materials such as PC Blend, ASA and ABS. The root cause it gives is a sudden temperature difference between the melting temperature at the nozzle and the ambient temperature around the print. The plastic cools, shrinks and warps.

Bambu Lab's wiki describes the same mechanism for its P2S and X2D printers: the outer edges of the print cool faster than the center, and the resulting thermal shrinkage tension pulls the corners of the first layer upward. In severe cases the model can detach from the plate or collapse.

1. Clean the build plate and match the plate type

Grease and dust are the most common reason a first layer lets go. Prusa recommends wiping the sheet with isopropyl alcohol of 90% or stronger, and notes that a thin layer of glue stick on a cold steel sheet can help adhesion and protect the surface. Bambu Lab recommends washing the plate with warm water and dish soap, drying it, and not touching the surface with bare hands afterwards.

Also check that the plate type chosen in the slicer matches the plate you are using. Bambu Lab points out that the same filament uses different heatbed temperatures on different plates, so the wrong selection can leave the bed too cool and cause warping.

2. Check the first layer and dry the filament

Sparse or poorly bonded first-layer lines make warping far more likely. Prusa suggests lowering the live Z adjustment slightly to improve adhesion, but warns against over-squishing the first layer. Our guide to fixing a bad first layer and the bed leveling guide cover this in detail.

Bambu Lab also lists moisture as a cause. It says moisture-prone filaments such as PETG become less stable during extrusion once they absorb water, which makes poor adhesion and warping more likely. See how to dry filament.

3. Keep the air around the print stable

Prusa advises keeping the ambient temperature stable for high-temperature filaments and keeping the printer away from open windows and air conditioning. For PC Blend, ASA and ABS it suggests an enclosure. It also notes that printing PLA or PETG in an enclosure might not be a good idea, because those materials need cooling. If you are weighing an enclosure, read enclosed vs open-frame 3D printers. Material specifics for ABS are in ABS print settings and how to stop ABS cracking.

A printed skirt used as a draft shield helps hold heat around the part, according to Prusa. Printing several objects at once also retains heat, and placing a problem part toward the center of the bed can help.

4. Tune part cooling

Cooling is a balance. Prusa says PLA and PETG need part cooling, so check the fan is on and try raising its speed if corners lift. For ABS and PC Blend it suggests trying low fan speeds of 10 to 20%. Too much fan can warp the whole object and weaken layer bonding, and if layer adhesion drops after raising the fan, Prusa says to raise the nozzle temperature to restore it.

Bambu Lab's P2S and X2D guide gives a specific starting point for those printers: set no cooling for the first 3 layers with the fan at 0, and reduce the auxiliary part cooling fan by about 20 to 30%, or set it to about 40 to 50%. Those values are for those printers, so treat them as an example rather than a universal rule.

5. Add a brim and slow down

A brim adds extra outlines around the first layer to increase contact area. Prusa recommends at least a 3 mm brim and calls it especially useful for tall objects with small bases and for several small objects printed together. Bambu Studio can also add brim ears only at the sharp corners that tend to lift, which saves material and cleanup. Our brim vs raft vs skirt page explains the options.

Slower printing helps too. Prusa says reducing print speed lets layers melt together properly and warp less.

Material notes

Prusa advises using the maker's default slicer profile for the material, since these are already refined. ABS, ASA and PC Blend warp most, PLA least. If you are choosing a filament partly to avoid warping, see PLA vs PETG vs ABS vs TPU.