How to Fix Warping in 3D Printing (ABS, PETG, PLA)
Warping — where corners lift off the bed mid-print — is especially common with ABS and PETG. Here's how to eliminate it with the right bed prep, enclosure tips, and slicer settings.
Warping happens when the outer edges or corners of a print curl upward and lift off the build plate. It's caused by thermal stress: the plastic contracts as it cools, and if the cooling is uneven (bottom hot from the bed, top cooling faster), it pulls the part into a curve.
Most affected materials: ABS, ASA, large PETG prints Rarely affected: PLA (unless very large flat parts)
Fix 1: Use an Enclosure (Essential for ABS/ASA)
ABS and ASA warp because they need to stay warm throughout the entire print, not just at the bed. An enclosure traps heat and keeps the ambient temperature around 40–50°C.
- Bambu X1C / P1S: Built-in enclosure — use it
- Prusa, Ender 3: Buy or build an enclosure (IKEA Lack table enclosure is a popular DIY option)
- No enclosure? ABS warping is almost unavoidable on open-frame printers for large parts
Fix 2: Increase Bed Temperature
Higher bed temps keep the base layer pliable longer, reducing the temperature differential.
| Material | Recommended Bed Temp |
|---|---|
| PLA | 55–65°C |
| PETG | 75–85°C |
| ABS | 105–115°C |
| ASA | 100–115°C |
Fix 3: Use Brim
A brim adds extra perimeter lines around the base of the print, increasing the surface area bonded to the bed. This resists the pulling forces of thermal contraction.
- Brim width: 5–10mm for most parts; up to 15–20mm for tall, narrow objects
- Brim lines: 5–10 lines in Cura
Enable brim in: Cura → Build Plate Adhesion → Brim | PrusaSlicer → Skirt and Brim
Fix 4: Improve Bed Surface Adhesion
| Material | Best Surface | Adhesion Helper |
|---|---|---|
| ABS | PEI or glass | ABS juice (dissolved ABS in acetone) or hairspray |
| ASA | PEI textured | Light hairspray or Magigoo ASA |
| PETG | Textured PEI | Usually none needed; avoid smooth PEI |
| PLA | Textured PEI | Usually none needed |
ABS juice recipe: Dissolve a few cm of failed ABS print in acetone, brush a thin coat on the bed, let dry before printing.
Fix 5: Eliminate Drafts
Even a small draft from a fan, door, or window can cause sudden cooling and warping. If you're printing ABS without an enclosure:
- Turn off room fans and AC
- Block airflow from the printer's part cooling fan (ABS typically prints with 0% part cooling)
- Close nearby doors/windows
Fix 6: First Layer Squish
A well-squished first layer (Z offset dialed in) bonds more surface area to the bed and resists warping better than a loose first layer.
Fix 7: Reduce Infill and Perimeter Stress
High infill percentages can create internal stresses that contribute to warping. For large flat parts:
- Try 15–20% infill instead of 50%+
- Use Gyroid or Lightning infill pattern (less directional stress than grid)
Material-Specific Tips
ABS: Enclosure is mandatory for anything larger than 5cm. Use ABS juice on glass. Print with 0% fan. Keep ambient temp 40–50°C.
ASA: Similar to ABS but slightly more tolerant. 5–10% fan is OK for overhangs. Outdoor performance is excellent.
PETG on large flat parts: Add brim, increase bed to 80°C, reduce cooling to 30–50%.
PLA warping: Usually only happens with very large, flat parts. Increase bed temp to 65°C, add brim, ensure bed is clean.