PETG vs ABS: Heat, Enclosures, Outdoor Use, and Printing

Who this comparison is for

This guide is for someone who has a job PLA can't do and is choosing the next material: a bracket for a car, a clip that lives outside, a housing near something warm, or a printer part. PETG and ABS are the two most common answers. They overlap a lot on paper, so the choice usually comes down to three questions:

• How hot will the part get?
• Is your printer enclosed?
• Can you ventilate the room where it prints?

Everything below comes from documentation published by Prusa Research, Bambu Lab, Polymaker, eSUN, and ELEGOO. Where we quote a figure, it describes one maker's product under that maker's test conditions. Other brands and grades differ, so check the data sheet for the exact spool you buy.

Is ABS more heat resistant than PETG?

Heat is the clearest reason to pick ABS. The fairest comparison is within one maker's data, because each maker tests its own way. Bambu Lab and Polymaker both publish heat deflection temperature (HDT) under ISO 75 for a PETG and an ABS:

To see the two ABS spools in that table side by side, read Bambu Lab ABS vs Polymaker PolyLite ABS. The PETG pair is in Bambu Lab PETG Basic vs Polymaker PETG.

Prusa doesn't publish an ABS figure in its ABS guide. It describes ABS as having "good high-temperature resistance." On the PETG side, Prusa's own pages don't quite agree. The Prusament PETG page lists a temperature resistance of 68 °C, and its data sheet gives an HDT of 68 °C at both 0.45 and 1.8 MPa. Prusa's PETG guide, however, says PETG parts suit "most exterior use (with temperatures below 80 °C)." If heat matters, design to the lower number.

Bambu Lab's filament guide groups PETG and ABS together as offering "better heat resistance" than PLA, and it classes PETG as a filament with a softening temperature of 60 to 80 ℃. eSUN's ABS+ page claims "Heat deflection up to 89'C" and mentions in-car heat exposure, but the same page's spec table and eSUN's ABS+ data sheet both list a heat distortion temperature of 73 °C (the data sheet cites GB/T 1634 and doesn't state the test load). We'd go by the data sheet. Our ABS vs ABS+ guide covers what eSUN's "plus" label does and doesn't change.

In practice, a part that will see the inside of a car on a summer day, or that sits next to a heat source, is where ABS earns its extra hassle. For a part that stays at room temperature or mildly warm, PETG is usually enough, and it's far easier to print.

Enclosure, warping, and which printers suit each

This is where the two materials differ most at the printer.

Does ABS need an enclosure?

Every maker we checked calls for an enclosed printer for ABS, though Polymaker allows small parts without one:

• Prusa: lists "Significant warping" and "Requires printer enclosure" as disadvantages, says "the printer should be inside an enclosure with a higher ambient temperature," and notes that ABS parts typically shrink "around 1-2%" as they cool.
• Bambu Lab: its filament guide says ABS, ASA, PC, and PA "Require higher heatbed and chamber temperatures to suppress warping and layer separation, and to ensure sufficient interlayer strength," and recommends an enclosed printer. Its ABS store page says "Enclosure Printers Required," and the Bambu ABS data sheet gives a chamber temperature of 45 to 60 °C.
• Polymaker: the PolyLite ABS data sheet lists a closure chamber as "Needed," and the product page says size matters. A non-enclosed printer at a 90 °C bed and 260 °C nozzle "can handle models smaller than fist size," bigger prints need an enclosed printer (about 40 to 50 °C), and models bigger than about 15 to 20 cm in any direction "will require an actively heated chamber (~70˚C+)."
• eSUN and ELEGOO: eSUN's ABS+ page says to "Print in an enclosed chamber with a stable temperature." ELEGOO's ABS page says "Enclosure Printer Required."

Without an enclosure, Prusa suggests PrusaSlicer's draft shield as a partial measure. Prusa also warns that printing inside an enclosure can deform the fan shroud and other plastic parts, and suggests reprinting those parts in a more heat-resistant material if they deform. Our enclosure planning guide covers what an enclosure does and doesn't do.

Does PETG need an enclosure?

PETG barely warps, and the makers that address it say it doesn't need an enclosure:

• Prusa: says it "does not shrink or warp (it has very little thermal expansion)," which makes it suitable for large models. The Prusament PETG page says "Enclosure not required."
• Polymaker: the data sheet lists a closure chamber as "Not Needed."
• eSUN: says its PETG "requires no heated enclosure."

Bambu Lab adds a nuance. Its filament guide says PETG suits open-frame or enclosed printers, but it adds: "For PETG and PETG-CF/GF, an enclosed printer is recommended to prevent low ambient temperatures from reducing the model's interlayer strength." Polymaker's PETG page similarly says closing the enclosure may help layer adhesion if you have one.

Too much chamber heat can cause a problem of its own with PETG. Bambu recommends opening the front door or removing the top glass cover on its enclosed printers so the filament doesn't soften in the extruder. Its own page gives two thresholds for this: the text says to do it when the bed is set above 60 ℃, while the plate table says to remove the glass cover when the bed is above 70 ℃. For ABS, the same table says "NO."

Which printers suit each

These fit notes come from printer makers' own documentation:

• Bambu Lab: the filament guide marks ABS as "Not Recommended" on open-frame printers (A Series, P1P) and "Recommended" on enclosed ones (H2 Series, X2D, P2S, X1 Series, P1S). PETG is "Compatible" on both. Bambu's A1 FAQ lists ABS among the high-temperature filaments the A1 can print, but it also says "We don't recommend enclosing the A1," so don't plan to make an A1 ABS-ready with a box.
• Prusa: the CORE One+ is an enclosed printer with a chamber that "heats up to 55 °C." Its spec table lists PETG as a supported material and ABS under "Advanced," while the page's filament cards rate PETG "Easy to print" and "ASA and ABS" as "Moderate." Prusa also says the printer "automatically opens the vent for low-temperature materials (PLA, PETG) and closes it for high-temp materials." For ABS on Prusa's open-frame printers, the ABS guide points to the Original Prusa Enclosure or a self-built one.
• Other printers: check your printer maker's enclosure and maximum nozzle temperature specs before buying ABS. Our printer pages summarize what each maker documents.

Is PETG or ABS better for outdoor use?

Both materials get used outdoors, but makers don't agree on ABS here.

• PETG: Prusa's PETG guide calls it "suitable for mechanical parts for both indoor and outdoor use" and lists it as "Water and humidity resistant." Bambu Lab says PETG Basic has "strong resistance to water, UV, and temperature" for outdoor applications. eSUN lists its PETG as "UV Resistant." Polymaker is more measured: "PETG is UV and water-resistant, making it suitable for outdoor parts, though prolonged exposure may degrade some properties."
• ABS: Prusa says ABS "Lacks UV resistance (unlike ASA)" and that "ABS parts used outdoor turn yellowish and more brittle over time." Bambu Lab's ABS data sheet, by contrast, opens by describing ABS as known for properties "such as high temperature resistance, UV resistance and water resistance." ELEGOO's ABS page claims water and cold resistance for "demanding outdoor uses" but doesn't mention UV.

If the part will sit in direct sun for years, look at ASA rather than ABS. Prusa's CORE One+ page describes ASA as "the material for outdoor applications where ABS would degrade," and our ABS vs ASA guide compares the two. For moderate outdoor use, the PETG makers above say their material is suitable.

Chemical resistance

Makers publish chemical-resistance data in different ways, so compare only within one maker's documents.

Polymaker rates both materials on the same scale in its data sheets:

Polymaker defines "Good" as possible "minor attack after long periods of storage," "Fair" as suitable for "short time contact," and "Poor" as "Material becomes unstable on contact with chemical at ambient temperature." Polymaker's PETG product page also describes the material as having "better water and chemical resistance," though it doesn't say better than what, and its own data sheet ratings don't show PETG ahead of PolyLite ABS.

Bambu Lab's data sheets point a different way on oils. Bambu ABS is listed as "Resistant" to acid and alkali but "Not resistant to some kinds of oil and grease." PETG Basic is "Not resistant" to acid and alkali but "Resistant to most kinds of oil and grease." Both are "Not resistant to some organic solvents."

Solvents: Prusa lists "Possibility of acetone smoothing and gluing" as an ABS advantage. For PETG, Prusa lists "Soluble in dangerous chemicals" as a drawback and says dissolving or smoothing it "is possible only in a laboratory by skilled lab workers using dangerous chemicals (Dichloromethane)." Our ABS vs ASA guide covers acetone safety, and we don't publish smoothing instructions.

If a part will touch a specific chemical, check that product's data sheet, and test a sample if it matters.

Fumes and ventilation

The makers' safety guidance is much stronger for ABS:

• Prusa lists "Potentially dangerous fumes (styrene)" as an ABS drawback and says to print it "in a well-ventilated room because the material releases fumes and substances that could pose a potential health risk," without creating a draft around the print.
• Bambu Lab's ABS page says "At printing temperatures, this filament may release harmful gases, including styrene, which can cause dizziness or nausea." It recommends a well-ventilated area or "an effective air filtration or exhaust system," a mask with a vapor filter for extended operation, and more ventilation or a pause if people with asthma or respiratory conditions, pregnant women, or children are present.
• Polymaker says PolyLite ABS uses a resin with "significantly lower volatile content than traditional ABS," but still says to "Print with an enclosure and good ventilation." eSUN's ABS+ page also says to "Ensure the printing area is well ventilated."

For PETG, Polymaker describes its PETG as "less odorous than ABS." Bambu Lab still asks you to print PETG Basic "in a well-ventilated area, or install an effective air filtration or exhaust system," the same wording it uses for ABS. Bambu's data sheets list both materials' odor as "Odorless," while its ABS store page warns that "Pungent and unpleasant odors may be released during printing." Low odor doesn't mean no emissions.

Printing temperatures

ABS runs hotter at both the nozzle and the bed. These are each maker's published starting points, not universal settings:

Even within one maker, the numbers shift between documents. Bambu's general guide and its product data sheets give different ranges, for example. Start from the profile for your exact spool. Before buying ABS, confirm that your hotend and bed are rated for these temperatures.

Part cooling differs too. Polymaker lists the fan "OFF" for PolyLite ABS and 20 to 60% for its PETG. Prusa recommends printing PETG's first few layers with the fan off, then at half power. Bambu's data sheets give 0 to 80% for ABS and 0 to 60% for PETG Basic.

Build surfaces

PETG's quirk is that it can stick too well. Prusa says "Do not print on the smooth PEI sheet as the adhesion may be too strong!" and recommends a powder-coated or satin sheet, or glue stick on smooth PEI if you use it anyway. For ABS, Prusa recommends "the smooth or powder-coated PEI sheet with a glue stick."

Bambu Lab lists both materials as "Not recommended" on its Cool Plate, and compatible with its Engineering, Smooth PEI, and Textured PEI plates. It recommends glue stick or liquid glue in general, and both of its data sheets call for glue. The PETG Basic data sheet also lists Cool Plate SuperTack, which is a different plate from the standard Cool Plate in the guide's table. Polymaker lists "PC and Textured PEI" for its PETG and "PC and Texture PEI (Glue when needed)" for PolyLite ABS.

See textured vs smooth build surfaces for more, and warping if ABS corners lift. If PETG sticks too hard or strings, see PETG printing problems.

Moisture and drying

Both absorb some moisture, and makers don't agree on which absorbs more:

• Bambu Lab lists saturated water absorption (25 °C, 55% RH) of 0.65% for Bambu ABS and 0.45% for PETG Basic.
• Polymaker lists an equilibrium water absorption of 0.35% for PolyLite ABS, and a maximum of 0.51% for Polymaker PETG at 70% RH. Those are different test conditions, so treat them as indicative only.

Drying guidance from the makers:

Bambu Lab's own PETG Basic data sheet gives 65 °C for 8 hours, lower than the generic PETG figure in its guide, so use the sheet for your exact spool. Polymaker says it is "highly recommended" to print and store its PETG from a PolyBox or PolyDryer box. Check that your dryer and spool can handle ABS's higher drying temperature. Our dryer vs dry box guide and stringing guide cover what damp filament does.

AMS and automatic feeding

Bambu Lab documents both materials for its AMS units, with one important difference:

• PETG: the filament guide lists PETG as "Compatible" with AMS and AMS lite, and the PETG Basic data sheet lists "AMS, AMS 2 PRO, AMS HT, AMS Lite."
• ABS: the filament guide lists "AMS: Compatible" but "AMS lite: Not Recommended." Bambu's ABS store page is firmer, saying "AMS lite NOT Compatible" alongside "AMS 2 Pro, AMS HT & AMS Compatible."

Drying in the AMS differs too. Bambu's guide lists ABS drying in the AMS 2 Pro as "Not recommended," while the AMS HT can dry it at 80 ℃ for 8 hours. PETG can be dried in either at 65 ℃ for 12 hours.

Polymaker says its PETG "works seamlessly with AMS and multi-material systems" and that its spools have hardened edges that "roll great in the AMS." For other brands and other multi-material systems, check the maker's own compatibility notes. Our AMS filament compatibility guide goes into spool sizes and feed paths.

Side-by-side comparison

All figures are manufacturer-published values for specific products. Other brands and grades differ.

Who should choose which

Choose PETG if:

• Your printer is open-frame, or it's a Bambu A1-series printer that Bambu says not to enclose.
• You can't vent fumes outdoors or add filtration.
• The part has to handle water, humidity, or moderate outdoor use rather than high heat.
• You print large parts and want low warping without a heated chamber.
• You feed filament from a Bambu AMS lite.

Choose ABS if:

• The part will see temperatures beyond what PETG makers rate their material for.
• You have an enclosed printer and a ventilated space, or filtration your printer maker recommends.
• You want to acetone-smooth or solvent-glue parts and can do it safely.

Who should skip both

• The part sits in strong sun for years. Prusa points to ASA for outdoor parts where ABS would degrade. See ABS vs ASA.
• The part is decorative and stays at room temperature. PLA is easier. See PLA vs PETG.
• You need safety-critical, food-contact, or child-use parts. Neither material solves that.

Quick answers

Is ABS more heat resistant than PETG? Yes, in the makers' own data. Bambu Lab's data sheets give Bambu ABS an HDT of 84 °C at 1.8 MPa against 68 °C for PETG Basic, and Polymaker's give PolyLite ABS 98 °C against 65 °C for Polymaker PETG.

Does PETG need an enclosure? Prusa, Polymaker, and eSUN say no. Bambu Lab recommends an enclosed printer for PETG so low ambient temperatures don't reduce interlayer strength, but also suggests opening the front door or removing the top glass cover at higher bed temperatures so PETG doesn't soften in the extruder.

Can a Bambu Lab A1 print ABS? Bambu's A1 FAQ lists ABS among the high-temperature filaments the A1 can print, but its filament guide marks ABS "Not Recommended" on open-frame printers, and the FAQ says "We don't recommend enclosing the A1."

Is PETG or ABS better outdoors? Prusa says ABS "Lacks UV resistance (unlike ASA)" and that outdoor ABS parts "turn yellowish and more brittle over time," while Bambu Lab's ABS data sheet describes ABS as UV resistant. Prusa and Bambu Lab describe PETG for outdoor use, and eSUN lists its PETG as "UV Resistant." For years of direct sun, Prusa points to ASA.

Can ABS go in a Bambu AMS lite? Bambu's filament guide marks ABS "Not Recommended" for the AMS lite, and its ABS store page says "AMS lite NOT Compatible." PETG is listed as "Compatible" with both the AMS and AMS lite.

Before you buy a spool

• Write down the highest temperature the part will see, and whether it lives outdoors or in sunlight.
• Check that your printer's hotend and bed reach the maker's recommended temperatures.
• For ABS, confirm your printer is enclosed and that its maker supports ABS on it.
• Plan ventilation separately from the enclosure.
• Check your build plate maker's guidance, especially PETG on smooth PEI.
• Plan drying and dry storage using the figures on your spool's data sheet.
• If you use an AMS or another automatic feeder, check the maker's compatibility list for that exact material.
• Read the data sheet for the exact product, since figures vary widely between brands.

Ready to choose? The PETG filament shortlist compares verified spools from standard to high-speed grades on their makers' data. The ABS filament shortlist matches verified ABS spools to the enclosed printers they suit. If you're adding a box around an open printer, start with the printer enclosures shortlist, and check your printer maker's guidance first.

PETG: what to check before you buy a spool ↗