Warping is the corners of a print pulling upward off the build plate as the part cools. It's a physics problem — every plastic shrinks as it cools, and big flat bottoms create big shrinkage forces. The fix is to either keep the part warm uniformly (enclosure) or to anchor it down so hard the shrinkage can't lift it (brim, mouse ears).
For PLA/PETG : close the doors and windows (eliminate drafts) and add a 5 mm brim. For ABS/ASA/PC : enclose the printer (Bambu X-series, Prusa CORE One, or a DIY box), use a 95–110 °C bed, and add an 8–10 mm brim. If only the corners lift, add mouse-ear discs at each corner instead of a full brim.
Every thermoplastic shrinks as it cools from melt to room temperature. The shrinkage rate varies wildly by material:
Shrinkage itself is uniform — the problem is differential cooling. The bottom of the part is held warm by the heated bed; the top is exposed to air. As the top cools faster, it shrinks first, and the resulting tension lifts the corners off the bed. Solve the temperature differential and you solve the warp.
The single most effective fix for ABS, ASA, PC, and nylon. An enclosure raises ambient temperature inside the print volume to 35–55 °C, dramatically reducing the temperature gradient.
The bed has to be hot enough to keep the first 1–2 mm of the print near the plastic's glass transition temperature (T g ). Below T g the plastic stiffens and the shrinkage forces win.
More bed-contact area = more force needed to lift the part. A brim is a single-layer skirt attached to the print's perimeter.
Long flat geometries warp more than tall narrow ones because there's more cooling differential across the width. Strategies:
Even with no enclosure, drafts are the #1 PLA/PETG warping cause. Common offenders:
If you can't enclose the printer, even a 3-sided cardboard wind-shield around it dramatically reduces warping on PLA and PETG.
For PC, nylon, and large ABS prints:
Part-cooling fans speed up the top-of-part cooling that drives the temperature differential. For warpy materials, dial part cooling back: