PETG

PETG is a go-to functional filament when you want more toughness and heat resistance than PLA, with a bit of flex instead of brittle snapping. It prints hot and “sticky,” so the two big success factors are (1) first-layer setup that avoids over-squish and bed damage, and (2) controlling ooze/stringing with the right temperature, retraction, travel behavior, and dry filament.

TL;DR

Print PETG hotter than PLA, but don’t over-squish the first layer; PETG can grab some beds hard enough to chip glass or pull up coatings. For stringing, dry the spool first, then drop nozzle temperature and tune retraction and travel.

PETG: your quick decision mapTopic-specific diagram for the concept, checks, and tradeoffs in this lesson.Dry spoolCompare tradeoffs before choosingSteady tempCompare tradeoffs before choosingCoolingCompare tradeoffs before choosingEasy finishCompare tradeoffs before choosing
This map highlights the two PETG make-or-break areas: first layer and stringing control.

What you’ll notice while printing

PETG’s two signature traits are sticky and stringy. Sticky means the first layer can bond aggressively, and the nozzle can plow through lines if your Z-offset is too low, leaving a rough first layer or even damaging the build surface. Stringy means it likes to ooze during travel moves, leaving wisps and tiny blobs—worse when you print too hot or the filament has absorbed moisture.

Typical PETG starting points (adjust per brand/printer)

Nozzle temperature
About 230–250 C. Lower temps usually cut stringing; higher temps usually increase layer bonding.
Bed temperature
About 70–90 C. Many printers keep the bed warm for the full print to reduce warping.
Part cooling fan
Use less than PLA. Too much fan can weaken layer bonding and make bridges more brittle.
Print speed
Moderate speeds work best. Slowing down often improves first-layer control and reduces nozzle drag on perimeters.

Stringing and blobs: fix them in this order

  1. Dry the filament first; wet PETG strings heavily and may pop or sizzle at the nozzle.
  2. Lower nozzle temperature in small steps (for example 5 C at a time) until stringing drops without hurting layer bonding.
  3. Tune retraction for your extruder: direct drive usually needs shorter retraction; Bowden usually needs longer—change one setting at a time.
  4. Increase travel speed if your machine stays accurate; faster travels give ooze less time to form strings.
  5. Reduce time spent hot and idle; use standby temps or a purge/prime step if your workflow supports it.

PETG vs PLA: quick rules of thumb

  • Choose PETG for tougher parts, warmer environments (like inside a car), and parts that get repeated impacts or handling.
  • Choose PLA for easier printing, sharper small details, and less stringing on most setups.
  • For very rigid thin features, PLA often feels stiffer; with PETG, plan on thicker walls, ribs, or a stiffer geometry.