Short answer: Warping happens because plastic shrinks as it cools, and the corners of your print cool fastest. To stop it: match the bed temperature to the material (PLA 50–60°C, PETG 70–80°C, ABS and ASA 90–100°C), keep moving air away from the print, add a brim on large flat parts, and print high-shrinkage materials like ABS and ASA in an enclosed printer such as the P1S or P2S. Here is the full checklist, tested daily in our Sydney workshop — we print every day, and warped corners are the single most common photo customers send us.
Why prints warp (30 seconds of physics)
Every filament shrinks slightly as it cools from printing temperature back to room temperature. The layers at the bottom of the print cooled and shrank ages ago; the fresh layers on top are still hot and still shrinking. That mismatch builds up internal stress, and the easiest place for that stress to release is at the corners — so the corners peel up off the plate.
The amount of shrinkage is the whole story. PLA shrinks very little, which is one reason it is the easiest material to print. ABS and ASA shrink a lot — enough that no build-plate glue in the world will hold a large ABS part flat on an open-frame printer in a cold room. That is why the fixes below are ordered from “applies to everything” to “applies to high-shrinkage materials”.
Fix 1: Get the first layer right before anything else
A part that warps was often never properly stuck down in the first place. The basics: wash your textured PEI plate with warm water and dishwashing liquid (not just a wipe — fingerprint oils survive a wipe), dry it with a clean towel, and let the printer run its full bed-levelling routine. If your first layer looks ropey or gappy, fix that first — our first layer adhesion guide covers calibration step by step. For PETG and ASA on a smooth PEI plate, a thin layer of glue stick acts as a release layer that paradoxically improves adhesion consistency and protects the plate.
Fix 2: Bed temperature is your anti-warp heater
The heated bed exists to keep the bottom layers of the print above the temperature where the plastic stiffens and starts pulling. Run it too cold and the corners lift; there is no prize for a cool bed. Real numbers that work on Bambu Lab machines:
| Material | Nozzle | Bed | Enclosure needed? |
|---|---|---|---|
| PLA | 190–220°C | 50–60°C | No — prefers open air |
| PETG | 230–250°C | 70–80°C | No, but keep draughts off it |
| ABS | 240–270°C | 90–100°C | Yes |
| ASA | 240–270°C | 90–100°C | Yes |
If a big PLA part is still lifting at 60°C, do not keep raising the bed — above about 65°C PLA goes soft at the base (it softens at 55–60°C) and you trade warping for elephant’s foot. Fix the airflow instead, below.
Fix 3: Control the air around the print
Warping is a cooling problem, so the air around the printer matters as much as the settings inside the slicer. Three situations we see constantly in Australia:
Air conditioning. A split-system blowing across the room is a corner-lifting machine. An open-frame printer like the A1 sitting in the airflow path will warp parts that print perfectly two metres away. Move the printer, or block the draught.
Cold garages in winter. A Sydney or Melbourne garage on a July morning can sit at 8–12°C. That widens the temperature gap the plastic falls through and makes every material warp-happier. An enclosure is the honest fix; for ABS and ASA it is non-negotiable, which is the main practical difference between the A1 and P1S — see our A1 vs P1S comparison.
Enclosed printers with the door open. On a P1S, print ABS and ASA with the door closed and the top glass on — the passive enclosure traps bed heat and that trapped warmth is what keeps big parts flat. For PLA it is the reverse: crack the door so heat escapes, or you invite stringing and heat creep. (The P2S manages this automatically with active chamber airflow, so its door stays shut for every material.) If stringing is your follow-on problem, our stringing guide has the 4-step fix.
Fix 4: Slicer settings that actually move the needle
In Bambu Studio, three settings do most of the anti-warp work. First, a brim: 5–8 mm of brim on any part with a footprint larger than your palm gives the corners nowhere to lift from — it is the cheapest insurance in 3D printing. Second, part cooling fan: for ABS and ASA, keep the part fan at 0–30%. Blasting a high-shrinkage material with room-temperature air mid-print is asking for delamination and curl. Third, first layer speed: slow it down and let the plastic be pressed into the plate texture rather than dragged across it. For very tall, thin ABS parts, enable the draft shield — a single-wall skirt printed at full height that acts as a windbreak inside the chamber.
Fix 5: Dry filament warps less
Wet filament adheres worse and prints with weaker layer bonds, and both show up as lifted corners and split layers. This matters more in Australia than most guides admit: coastal cities sit at 60–80% relative humidity for much of the year, and PETG, ASA and ABS all drink moisture on an open shelf. If your spools live outside a dry box, read our filament storage guide for Australia — drying a suspect spool before a big print is often the difference between a flat part and a Tuesday-night failure. Bambu Lab’s own wiki publishes recommended drying times per material if you want the official numbers.
Which material should you even be printing?
Sometimes the right fix is a different spool. If you are fighting to keep ABS flat on an open-frame A1, the better answer is usually PETG Basic — on an open-frame machine it is the best strength-per-dollar choice and it warps far less than ABS. If the part lives outdoors under Australian UV, skip ABS entirely and print ASA in an enclosed machine — our ASA outdoor guide explains why it should be a staple here, not a niche material. And if you are still choosing a material, start with our Australian filament buying guide or browse the full filament range.
FAQ
Why do my ABS prints warp even with the P1S door closed?
Usually the chamber never got warm. The P1S enclosure is passively heated by the bed, so give it a head start: preheat the bed at 90–100°C for 10–15 minutes with the door and top closed before starting a large ABS print, and keep the printer out of cold rooms. Placement helps too — centre the part and orient long flat edges away from the door.
Does glue stick stop warping?
Glue improves the grip between plastic and plate, so it helps with small and medium parts. It cannot beat the shrinkage force of a large ABS or ASA part on a cold printer — adhesive is one leg of the fix, temperature and enclosure are the others.
Can I print ABS on the Bambu Lab A1?
Not reliably — the A1 is open-frame, and ABS needs trapped chamber heat. Small ABS parts might survive on a still, warm day; large ones will curl. On an A1, print PETG when you need strength, or step up to an enclosed P1S or P2S for ABS and ASA.
Why do only my large flat parts warp?
Shrinkage stress scales with the length of the part — a 200 mm flat base accumulates far more pull at its corners than a 40 mm one, in every material. Big flat parts deserve the full treatment: brim, correct bed temperature, no draughts. Rounding the corners of your design (fillets instead of sharp 90° corners) also measurably reduces lifting.
3D BRO is an authorised Bambu Lab reseller and Australia’s authorised Bambu Lab service centre, with stock in Regents Park, Sydney and fast Australia-wide shipping. Browse Bambu Lab printers and accessories or the full filament collection — and if a print still will not stay flat, get in touch and send us a photo. We print every day; we have seen it before.
