Starting point
These are the numbers I go back to before touching anything else, across three different printers and two different PETG brands — a genuinely reliable starting point rather than a fresh guess every time a new spool goes on.
Temperatures
- Nozzle: 235–245°C
- Bed: 70–80°C
The range matters more than any single number — different brands of PETG behave noticeably differently even at the same nominal temperature, and starting at the lower end and nudging up if layers aren't bonding has been more reliable than starting high and fighting stringing.
Speed
Slower than PLA everywhere, especially on the first three layers — PETG punishes rushing far more than it punishes patience, and a bed adhesion failure on layer two costs far more time than the print would have saved by running faster.
Retraction is the other place PETG differs sharply from PLA: shorter retraction distances at a slower speed avoid the stringing that longer, faster PLA-style retraction settings tend to cause. It took several failed prints before I stopped copying PLA settings wholesale and actually tuned for the material in front of me.
None of this is exotic advice, but it's the specific combination that's worked consistently enough for me to stop second-guessing it before every print.