PETG prints at a nozzle temperature of 230–250°C and a bed temperature of 70–85°C, with slower speeds and less cooling than you’d use for PLA. It’s one of the most practical filaments available: stronger and more heat-resistant than PLA, easier to print than ABS, and it produces significantly fewer fumes. Getting good results comes down to dialing in a handful of settings and understanding how the material behaves differently from what you’re used to.
Temperature Settings
PETG’s working range is 220–260°C at the nozzle, but most brands print best between 235 and 250°C. A good starting point is 240°C for your first layer, then 235–245°C for the rest of the print. If you want maximum layer strength (for functional parts, brackets, or anything load-bearing), push the nozzle up toward 255°C. Too low and layers won’t fuse properly; too high and you’ll get excessive oozing and blobs.
Set your heated bed to 70–85°C. Glass beds tend to need the higher end of that range for reliable adhesion. If you’re printing on a PEI sheet or textured build plate, 70–75°C is usually enough. Give the bed a minute or two to stabilize at temperature before starting your print.
Print Speed
Most printers handle PETG well at 60–80 mm/s. If you’re on a standard Ender 3 or similar budget printer, drop that to 40–60 mm/s for more consistent results. High-speed machines like Bambu Lab or Voron printers can push PETG well past 100 mm/s with the right profiles, but if you’re new to the material, start slower and work up.
Slower first layers help with adhesion. Printing your initial layer at 50–70% of your normal speed gives the filament time to bond to the build surface before the rest of the print stacks on top.
Bed Adhesion and Build Surfaces
PETG sticks to build surfaces aggressively, which is both its strength and its biggest headache. On bare glass, PETG can bond so firmly that removing your print tears chunks out of the glass surface. If you’re using a glass bed, always apply a release agent like glue stick or hairspray. This sounds counterintuitive since those products are usually used to improve adhesion, but with PETG they create a sacrificial layer between the filament and the glass.
Textured PEI sheets are the most popular surface for PETG. Parts grip well during printing and pop off cleanly once the bed cools. Smooth PEI works too, but can sometimes bond too strongly, so a light wipe of glue stick helps there as well. Whatever surface you use, make sure your Z offset gives the first layer enough space. PETG doesn’t like being squished as flat as PLA. If your nozzle is too close to the bed, you’ll get a rough first layer with material dragging and sticking to the nozzle.
Cooling Fan Settings
This is where PETG diverges most from PLA. Where PLA wants full fan speed, PETG needs much less cooling. Run your part cooling fan at 30–50% for most of the print. Too much cooling weakens layer bonds, making your part brittle instead of tough. Too little cooling causes sagging on overhangs and bridges.
Turn the fan off entirely for the first two or three layers to maximize bed adhesion. For overhangs and bridging sections, your slicer can automatically bump fan speed higher, which is fine. The key is keeping it moderate on normal perimeters and infill. If you’re printing a purely functional part where appearance doesn’t matter, you can drop the fan even lower (or off entirely) for the strongest possible layer fusion.
Retraction Settings to Reduce Stringing
PETG is stringy by nature. The melted filament stays fluid longer than PLA, so it tends to leave thin wisps between travel moves. Retraction settings are your main tool for controlling this.
For a direct drive extruder, start with a retraction distance of 0.5–2 mm at a speed of 25–35 mm/s. Bowden tube setups need more distance, typically 3–6 mm, because the tube itself has slack. Going beyond these ranges often causes clogs rather than solving stringing. Retraction speed between 20 and 45 mm/s works for most setups, but going too fast can grind the filament.
Two slicer settings that help beyond basic retraction: enable Z hop (which lifts the nozzle slightly during travel moves so it doesn’t drag through your print) and turn on “avoid crossing walls” or “avoid crossing perimeters.” That second option reroutes travel moves to stay inside the print whenever possible, which dramatically cuts down on visible strings on outer surfaces.
Dealing With Blobs and Nozzle Buildup
PETG loves to stick to the nozzle. Small bits of filament accumulate on the outside of the nozzle tip, form a blob, and eventually fall onto your print, leaving ugly bumps. Several things contribute to this problem.
Moisture is the most common cause. Wet PETG produces tiny steam bubbles that push filament out unpredictably, and that excess material collects on the nozzle. If you’re seeing frequent blobbing, dry your filament before anything else (more on that below). Beyond moisture, check that your flow rate isn’t set too high. Even 2–3% excess flow creates enough extra material to build up on the nozzle over a long print. Pressure advance (or linear advance, depending on your firmware) also matters: if the value is too low, filament oozes at the start and end of each line, feeding the blob cycle.
A Z offset that’s slightly too close to the bed on the first layer can start the problem early. PETG curls upward at the edges when squished too flat, and those curled edges catch on the nozzle. Increasing your Z offset by about 0.05 mm compared to your PLA profile often fixes first-layer nozzle scraping.
Keeping Your Filament Dry
PETG absorbs moisture from the air, and wet filament causes popping sounds during extrusion, rough surface texture, poor layer adhesion, and the blobbing described above. If your spool has been sitting out for more than a few weeks in a humid environment, it’s worth drying before use.
In a food dehydrator or filament dryer, set the temperature to 60–65°C and dry for at least 8 hours. If your printer has a heated bed drying function (common on Bambu Lab machines), set the bed to 75–85°C and allow about 12 hours. Once dried, store the spool in a sealed container or vacuum bag with desiccant packets. Printing directly from a dry box is ideal for long prints in humid climates.
Nozzle and Hardware Considerations
Standard brass nozzles work perfectly fine with PETG. The filament is not abrasive, so there’s no need to upgrade to hardened steel unless you’re also printing carbon fiber or glass fiber composites. Brass actually performs slightly better for PETG because it conducts heat more efficiently, giving you more consistent extrusion.
If your printer has an all-metal hotend, you’re set. PTFE-lined hotends (common on budget printers) can handle PETG’s temperature range, but the PTFE tube will degrade faster at the upper end of the range (250°C+). If you plan to print PETG regularly at higher temperatures, upgrading to an all-metal hotend extends the life of your setup and eliminates any risk of PTFE off-gassing.
Fumes and Ventilation
PETG produces significantly fewer volatile organic compounds than ABS. In laboratory testing, PETG’s emission rates were more than ten times lower than ABS, with the fewest identified compounds of any common filament tested. The primary compound released is acetaldehyde, in small quantities. You don’t need an enclosure for fume control (though enclosures help with temperature stability on tall prints). Basic room ventilation, like an open window or a desk fan pointed toward a window, is sufficient for most printing environments. Researchers have specifically recommended PETG as a safer alternative to ABS for home use where proper ventilation can’t always be guaranteed.
Why PETG Over PLA or ABS
PETG sits in a practical middle ground. PLA is easier to print but brittle and softens at relatively low temperatures, meaning parts left in a hot car or used outdoors in summer can warp. ABS is tougher but requires an enclosure, produces harsh fumes, and warps aggressively. PETG gives you better impact resistance than PLA, better chemical resistance, and a higher working temperature, all without needing an enclosure or worrying about excessive fumes. It’s the go-to choice for functional parts, outdoor items, food-adjacent containers (though food safety depends on print layer gaps, not just material), and anything that needs to survive real-world stress.