ABS was the default filament before PLA took over, and it still beats PLA and PETG on heat resistance and impact strength without moving up to nylon or polycarbonate. The tradeoff is that ABS is far less forgiving to print: it needs more heat at the nozzle and bed, it warps if the surrounding air isn’t stable, and it puts more fumes into the room than PLA or PETG. This guide covers the nozzle and bed temperature ranges ABS spools call for, why an enclosure matters more here than for almost any other filament, why the cooling fan runs opposite to how it does on PLA, print speed, ventilation, and how to tell warping apart from a print that’s actually delaminating. For fixing warping once it has started, see the dedicated ABS warping guide; for how ABS compares to other materials before you commit a spool, see the 3D printer filament types guide. For a direct look at whether the extra heat resistance of polycarbonate is worth it, see the PC vs ABS comparison, or the ABS vs nylon comparison if wear resistance and strength matter more than moderate heat resistance.
Nozzle temperature: why ABS runs hotter than PLA or PETG
Most ABS prints well between 230°C and 260°C, above PLA’s 190-220°C window and a step above PETG’s 230-250°C range. Prusa’s knowledge base lists 255°C as its recommended nozzle temperature for Prusament ABS, while Overture’s data sheet gives a somewhat lower 230-250°C. Start near the middle of the range printed on your spool and adjust from how the layers bond: too cold and layers separate under load, too hot and you get stringing, sagging overhangs, or a surface that looks glossy and slightly melted instead of crisp. ABS stays sensitive to temperature swings through the print more than PLA does, so a poorly seated thermistor shows up as a visible defect faster than it would on a more forgiving material.
Bed temperature and why a heated bed is mandatory
ABS needs real bed heat to stick, typically somewhere in the 90-110°C range. Prusa’s knowledge base recommends 100°C as a default and allows a wider 80-110°C window depending on the size of the part, since a larger footprint generates more shrinkage force and needs a hotter, more even bed to counter it. An unheated bed isn’t a workable option the way it sometimes is for PLA: without real heat the first layer cools and contracts almost immediately, and the corners start lifting before the print gets past its first few layers. A smooth or powder-coated PEI sheet with a thin glue stick coat is a reasonable starting surface. ABS also shrinks a little as it cools even under good conditions, generally in the range of 1-2% according to Prusa’s own figures, so a dimensionally critical part is worth test-printing and measuring first.
Enclosure: why still, warm air matters more here than for any other common filament
ABS shrinks noticeably more than PLA or PETG as it cools, and that shrinkage keeps happening well after the plastic has left the nozzle. If one part of a print cools faster than another, a draft from an open window, an AC vent, or a fan blowing on one side, the two areas contract at different rates and pull apart at the layer lines or lift off the bed. An enclosure keeps the air around the part at a stable, warm temperature so the whole piece cools at roughly the same rate. Prusa’s own guidance is direct about it: keep the printer inside an enclosure with an elevated ambient temperature, and if you don’t have one, turn on the draft shield option in the slicer as a partial substitute for small parts. See the 3D printer enclosure guide for what to look for in one. If you need UV resistance for an outdoor part rather than just a warping workaround, ASA solves the same shrinkage problem with better weathering; see the ABS vs ASA comparison and the ASA print settings guide for its own numbers.
Cooling fan: low or off, the opposite of PLA
This is the setting most people coming from PLA get backwards. PLA wants strong part cooling, often 80-100% fan from the second layer up, to hold sharp overhangs and clean bridges. ABS wants close to the opposite: blowing cool air directly onto freshly extruded ABS cools that one spot faster than the rest of the layer around it, which is exactly the uneven cooling that causes warping and layer splitting in the first place. Common practice is to leave the fan off for most of the print, or cap it around 20-30% and only after the first several layers are down, using just enough airflow to firm up small overhangs and bridges rather than to cool the whole part. See the PLA print settings guide for comparison. Fan speed is one of the few settings where PLA and ABS point in genuinely opposite directions.
Print speed
ABS generally prints in the 30-60mm/s range for walls and infill, with the first few layers slower, often 10-20mm/s, to give the bed the best chance at holding the part down. Slower speed gives each layer more time to bond to the one beneath it before the next pass, and reduces the mechanical stress that later shows up as warping or a lifted corner. Pushing speed too high on ABS shows up as a defect faster and more severely than on PLA, so dropping speed is a reasonable first move when a print misbehaves.
Ventilation and fumes
Heating ABS releases styrene fumes along with ultrafine particles, and styrene itself is classified by the International Agency for Research on Cancer as a possible human carcinogen. Short exposures can cause headaches and eye or throat irritation, and repeated exposure in an unventilated room is worth avoiding. Print ABS somewhere with real airflow, ideally an enclosure vented outside or filtered through activated carbon, rather than a closed bedroom or small office. This doesn’t conflict with keeping the air around the part itself still: the goal is to move air through the room generally, not to aim a fan or an open window directly at the print, which brings back the warping problem the enclosure was solving.
Warping vs delamination: two different problems that look similar
Warping and delamination share a root cause, the internal stress that builds as ABS shrinks while cooling, but they aren’t the same failure and don’t always call for the same fix. Warping shows up at the base of a print: the corners lose their grip on the bed and curl upward, usually from uneven cooling or a draft hitting one side. Delamination shows up higher on the print, sometimes anywhere along a tall wall, as layers actually separate or crack apart rather than lift off the plate. It’s more often caused by a nozzle temperature that’s too low, a print speed too fast for the layer to bond, or, on ABS specifically, too much cooling fan working against the layer’s ability to fuse with the one below it. If corners are lifting, start with the enclosure and bed temperature advice above; the ABS warping guide goes further into fixing it. Seeing cracks mid-print instead? Check nozzle temperature and fan speed before assuming it’s a warping problem.
ABS settings checklist
- Nozzle temperature set within 230-260°C, starting near the middle of the spool’s printed range.
- Bed temperature between 90°C and 110°C on a PEI or glue-stick-prepped surface.
- Enclosure or draft shield in place to keep the air around the part still and warm.
- Cooling fan off or under roughly 30%, the opposite of PLA’s high-cooling default.
- Print speed kept moderate, roughly 30-60mm/s, slower for the first layers.
- Printed in a ventilated space, with airflow through the room rather than a draft on the part.