Quick diagnosis
ABS does not warp the way PETG or PLA do. The PETG warping guide here is mostly about resisting the urge to add heat to a filament that already grips the bed too well, and the PLA warping guide spends most of its time ruling out other problems, since real PLA warping is genuinely uncommon. ABS sits at the other end of the spectrum: it shrinks substantially more than either as it cools, and the real fix is usually a heated, enclosed chamber, not a draft shield. For the shared fundamentals, first-layer contact, drafts, bed temperature testing, brim, and orientation, start with the general warping checklist; this guide covers what is specific to ABS.
1. Why ABS shrinks more as it cools
ABS is an amorphous thermoplastic, the same broad family as PETG and PLA, but its glass transition temperature sits much higher: typically 105 to 110 degrees Celsius, against roughly 80 for PETG and around 60 for PLA. A material locks its shape in near that point, so ABS keeps contracting through a much wider range before it fully sets. Add a higher coefficient of thermal expansion, and that wider drop means noticeably more shrinkage across a print. The stress builds as outer walls cool faster than the core, and it concentrates wherever the print has the weakest grip: usually the corners farthest from the bed’s center.
2. Bed temperature that actually holds ABS down
PLA prints happily around 50 to 60 degrees and PETG usually sits at 70 to 80, but ABS needs to run considerably hotter to keep its base layer above the material’s own glass transition point for as long as possible. Prusa’s guidance centers on 100 degrees Celsius, with a working range of about 80 to 110 depending on the part’s footprint, since larger parts generate more shrinkage force. Overture, among other filament makers, lands in a similar 80 to 100 degree band. Whatever number you settle on, check it at the corners and edges of the bed, not just the center; the general warping checklist covers how to test that properly.
3. Why ABS wants an enclosure, not just a draft shield
A slicer draft shield can be enough for a small PLA or PETG part, but ABS genuinely benefits from, and on larger prints often needs, a real heated chamber. Polymaker’s ABS Pro line calls for a chamber of 50 degrees Celsius or higher, with the bed preheated around ten minutes before the print starts so the enclosure catches up, and its faster ABS Max variant asks for an actively heated chamber above 65 degrees. Prusa’s own approach is similar: enclose the printer and treat the draft shield as a fallback for small parts, not a substitute. Holding the surrounding air somewhere in the 40 to 60 degree range keeps the outer walls from cooling and shrinking faster than the core, which is what pulls ABS corners up in the first place.
4. Adhesion aids built for ABS, not borrowed from PETG
PETG grips bare glass or a PEI sheet so well that the bigger risk is not getting a print off the bed afterward, which is why that guide barely mentions adhesion aids. ABS is the opposite case. The classic fix is ABS slurry, sometimes called ABS juice: scrap ABS dissolved in acetone until it forms a thin, milky liquid, then wiped onto glass or Kapton tape as a thin coat. ABS bonds strongly to itself, so this microscopic layer gives the first layer something it actually wants to stick to. A plain glue stick on a PEI sheet is a simpler, less smelly alternative that Prusa recommends as a starting point. Apply either one thin and even; a thick coat just trades one adhesion problem for another.
5. Warping is not the same failure as cracking
Warping and layer separation share a cause, the internal stress that builds as ABS shrinks while cooling, but they show up in different places. Warping is a bed adhesion failure: the base loses its grip and the corners peel upward. Delamination is a bond failure between layers higher up, most often on tall prints where the temperature gap between a fresh layer and the one beneath it is largest. Fixing warping with a hotter bed and an enclosure usually lowers the risk of the other too, since both respond to the same shrinkage. If what you are seeing is horizontal cracks rather than lifted corners, the dedicated layer separation guide is the more direct fix.
ABS gives off styrene fumes and fine particles while printing, more so inside a closed, heated enclosure. Vent it outside if you can, or filter it with activated carbon, and keep the room ventilated during and after the print.
ABS warping checklist
- Set the bed to 90-110°C and check the temperature at the corners, not just the center.
- Enclose the printer; a heated chamber in the 40-60°C range beats a draft shield past small parts.
- Preheat the bed and chamber together for several minutes before printing.
- Use ABS slurry on glass or Kapton, or a glue stick on PEI, for a surface ABS actually bonds to.
- Keep the room ventilated and vent the enclosure outside if you can.
- Seeing cracks between layers instead of lifted corners? Check the layer separation guide instead.