PETG Print Temperature: Nozzle and Bed Settings

PETG prints hotter than PLA and needs a heated bed. Prusa recommends 230 degrees C for the first layer and 240 for the others, with the bed at 85 degrees C for the first layer and 90 for the rest. Polymaker's PETG lists 240 to 260 degrees C at the nozzle and 60 to 70 degrees C on the bed. The settings differ because the products and printers differ, which is why the spool label always wins over a chart.

This is a research article built from manufacturer documentation (sources below). It does not describe our own prints, and every figure is a starting point.

PETG temperature settings at a glance

The bed figures are far apart. Prusa's profile is tuned for its own steel sheets, and Polymaker's is a general range for many printers. Start near the lower end of a maker's range and raise the bed only if adhesion is poor.

Nozzle temperature

Prusa explains the trade-off: higher filament temperature improves merging between layers, which gives better mechanical strength. Higher temperature also makes PETG ooze and string more. Its guidance for stringing is higher retraction and a lower nozzle temperature, or using the PrusaSlicer profiles.

Tuning method

1. Start at the middle of the range on the spool, or 240 degrees C if the label is missing.
2. If you see strings or blobs, lower the temperature by 5 degrees C and print the same small test again. The guide to fixing stringing lists the other causes in order.
3. If layers split or the print looks weak, raise the temperature by 5 degrees C or slow down.
4. Keep notes by brand and color. Two PETG spools from different makers can behave differently.

Bed temperature and the build plate

Unlike PLA, PETG requires a heated bed according to Prusa. The bigger problem is adhesion that is too strong. Prusa warns against printing PETG directly on a smooth PEI sheet because the bond can be strong enough to damage the sheet, and recommends a powder-coated textured or satin sheet. If you do use smooth PEI, Prusa says to apply a glue stick first. Keep the plate clean as well.

If the first layer does not stick or leaves gaps, work through fixing a bad first layer before changing temperatures.

Cooling

Prusa's advice is nuanced. Cooling keeps the model detailed and reduces stringing and oozing. But if you want the toughest part, turn the fan off, because hotter layers bond better. Its general recommendation is to print the first few layers with the fan off to prevent deformation, then run it at about half power. Polymaker lists the fan at 20% to 60%.

Speed and retraction

Polymaker states a speed of up to 300 mm/s for its PETG, which depends on a printer built for that speed. Slower speeds are safer if your printer is older or you see under-extrusion. Retraction starting points from Polymaker are 1 mm at 20 mm/s for direct drive, 3 mm at 40 mm/s for Bowden setups.

What PETG is good for, and where temperature matters

• Mechanical parts: Prusa notes PETG's good temperature resistance makes it suitable for most interior and exterior use with temperatures below 80 degrees C. It also lists poor bridging and overhangs, stringing and hard-to-remove supports as drawbacks.
• Layer adhesion: Prusa lists PETG as having good layer adhesion and being water and humidity resistant.
• Moisture: PETG strings badly when wet. See how to store filament and how to dry filament.

For a comparison with PLA and ABS, see PETG vs PLA and PLA vs PETG vs ABS vs TPU. For the PLA equivalent of this page, see PLA print temperature.

Common mistakes

• Printing PETG on a smooth PEI plate with no release layer. The bond can be too strong, per Prusa.
• Using PLA fan settings. Full fan from the first layers can cause deformation and poor bonding.
• Setting the nozzle too close. A very low nozzle makes PETG blobs and sticks to the nozzle.
• Chasing temperature when the spool is wet. Dry the spool first.