PLA vs PETG: Which Filament Should You Print With?

PLA prints hotter than room temperature but cooler than almost anything else on the market, comes off the bed with less warping, and is the easier of the two filaments to get a clean first print from. PETG needs a hotter nozzle and a hotter bed, but it shrugs off heat and impact that would crack or sag a PLA part. The numbers below are read straight from filament makers’ own technical data sheets, not estimated, so you can match them against your printer’s limits before you load a spool. This guide relies on published data sheets, the CPSC recall database, and independent measurements from named testers like CNC Kitchen, not on a lab of our own; see how we check our numbers at /how-we-score/.

How do PLA and PETG differ in print temperature and bed temperature?

PLA prints at 190°C to 230°C at the nozzle with a bed at 25°C to 60°C, while PETG needs 240°C to 260°C at the nozzle and a bed at 60°C to 70°C, based on Polymaker’s technical data sheets for PolyLite PLA and Polymaker PETG. That 50°C jump in nozzle temperature and 10°C to 35°C jump in bed temperature is the first thing to check: some budget printers cap their bed heater around 60°C to 70°C, which puts PETG at the very top of what they can do, and a few cannot reach 260°C at the nozzle at all without an upgraded hot end.

How do you decide between PLA and PETG? Follow these 5 steps

1. Check your printer’s bed temperature ceiling. If it cannot hold 60°C to 70°C at the bed, PETG will lift at the corners and you should stay with PLA.
2. Match heat exposure to the softening point. PLA’s Vicat softening point is 63°C. PETG’s is 75°C, with a heat deflection temperature of 65°C at 1.8 MPa load. Anything that sits in direct sun, like a dashboard mount, leans toward PETG.
3. Weigh how much flex or impact the part needs. PETG stretches to 9.33% elongation at break before snapping versus 1.9% for PLA (both X-Y, ISO 527). A part that gets dropped is safer in PETG.
4. Dry your PETG before printing. Polymaker’s data sheet calls for 55°C for 6 hours if the spool has absorbed moisture. Skipping this is the top cause of stringy, bubbly PETG prints.
5. Price the spool against the job. PolyLite PLA lists at $19.99 per 1kg spool on Polymaker’s store, Polymaker PETG at $18.99. That gap is too small to be the deciding factor, so pick PLA for indoor, low-heat parts and PETG for anything exposed to heat, flex, or the outdoors.

How much stronger and more flexible is PETG than PLA?

PETG bends further before it breaks, while PLA is slightly stronger in a straight pull but far more brittle. Polymaker’s data sheets put PLA’s tensile strength at 46.6 MPa (X-Y) with 1.9% elongation at break, against PETG’s 47.96 MPa (X-Y) with 9.33% elongation at break. The tensile numbers are close enough to call a draw, but the elongation gap is not: PETG stretches roughly five times further before snapping, which is why PETG parts survive drops and PLA parts tend to crack along a layer line instead of bending.

How much heat can PLA and PETG handle before they soften?

PETG holds its shape about 10°C to 14°C higher than PLA before softening, based on Vicat testing (ISO 306) for both: 63°C for PLA versus 75°C for PETG. That gap matters in the sun. A joint study by Arizona State University and the University of California, San Diego found a vehicle parked in direct sun for one hour reached an average dashboard temperature of 157°F (about 69°C), with dark surfaces sometimes climbing to 180°F to 200°F (82°C to 93°C). A PLA phone mount on that dashboard will likely sag; PETG has more margin but is not guaranteed to survive the hottest peaks either.

Why does PETG string more, and how do you fix it?

PETG oozes more between moves because it prints hotter and flows more freely when idle, so Polymaker’s own settings call for the cooling fan off to 20% and 1mm to 3mm of retraction, versus PLA’s fan-on, 1mm setup. If you see fine hairs on a PETG print, raise retraction in 0.5mm steps, drop nozzle temperature 5°C at a time toward the 240°C floor, and confirm the spool was dried at 55°C for 6 hours first, since wet PETG strings even with perfect retraction settings.

Is 3D printed PLA or PETG safe for food contact?

Neither is food safe straight off the printer, regardless of resin. Prusa’s knowledge base states that the grooves between printed layers are “a seedbed for bacteria as they are almost impossible to clean properly,” and that colorants in standard filament are not guaranteed food-neutral even when the base resin is. A standard brass nozzle adds another problem: as it wears, that metal ends up in the print. Prusa’s conclusion is direct: “We do not recommend using 3d-prints as food-containers etc.” A part that touches food needs certified food-grade filament, a stainless or titanium nozzle, and usually a food-safe coating, not just a switch from PLA to PETG.

How does the 3-year cost compare?

At prices read from Polymaker’s own store, a 1kg spool is close to a wash: PolyLite PLA at $19.99 versus Polymaker PETG at $18.99. The bigger three-year cost driver is usually failed prints and hardware, not the resin: PETG’s higher nozzle temperature wears a stock brass nozzle faster, and a poorly leveled bed causes more first-layer failures with PLA’s lighter adhesion. Choose by the part’s job first and let cost be the tiebreaker. For machines that handle both filaments well, including enclosed chambers for PETG, see our guide to the best 3D printers.

What are the most common mistakes when switching between PLA and PETG?

• Leaving the cooling fan on full for PETG. PLA wants the fan on; PETG wants it off to 20%, per Polymaker’s settings. Full cooling on PETG causes weak layer bonding.
• Reusing PLA retraction settings for PETG. PETG needs 1mm to 3mm of retraction versus PLA’s 1mm. Under-retracting PETG is the top cause of stringing.
• Printing PETG straight out of a humid room. Dry it at 55°C for 6 hours first if it has been open more than a few days.
• Assuming a part is heat-safe because it “feels like PLA.” PLA softens at 61°C to 63°C, below a warm car interior or sunny windowsill.
• Ignoring the bed temperature ceiling. If your bed cannot hold 60°C or higher, PETG corners will lift no matter how good your settings are.

When should you replace a spool of PLA or PETG?

Replace a spool when it snaps cleanly instead of bending as you unspool it, when it has visibly yellowed from UV exposure, or when a PETG spool keeps popping or stringing even after a proper 55°C, 6-hour dry cycle. Store both filaments in a sealed container with desiccant. PETG is more hygroscopic and needs drying sooner than PLA in a humid workshop.

FAQ

Can I print PLA and PETG on the same printer without upgrades?

Usually yes, as long as the printer can reach 260°C at the nozzle and hold 60°C to 70°C at the bed.

Is PETG stronger than PLA?

Tensile strength is close (46.6 MPa for PLA versus 47.96 MPa for PETG, both X-Y), but PETG is far more flexible, with about five times the elongation at break of PLA.

Does PETG need a heated enclosure?

No, but an enclosed chamber helps large parts by reducing warping and uneven cooling.

Can I use PLA outdoors?

Only for short-term or shaded use. PLA’s Vicat softening point is 63°C, which many outdoor surfaces exceed in direct summer sun.

Why does my PETG print have blobs or bubbles?

That is almost always moisture. Dry the spool at 55°C for 6 hours and reprint before changing any other setting.