How to dry PETG: temperatures, times, and safe methods

Short answer

Dry PETG at 60 to 65 C for 6 to 8 hours in a filament dryer or food dehydrator. PETG is hygroscopic, so a spool left open goes wet fast, and a wet spool pops, strings, and prints cloudy. Per Bambu’s PETG guide, 60 to 65 C is the safe drying range, and the Polymaker PETG datasheet lists a similar 55 C baseline, so hold the heat in that band and store the spool sealed after.

Why PETG needs drying

PETG pulls moisture out of the air faster than PLA, so a spool left on the printer for a few days in a humid room can already be wet. The water boils at the nozzle, so you hear popping or hissing, the surface turns cloudy or rough, and fine strings appear between moves. None of those prove the PETG is wet on their own, but two or three together point to a spool that needs drying.

The fix is heat held low and steady, long enough to drive the moisture back out. Dry the spool once, then store it sealed so you do not repeat the cycle every week.

PETG drying methods

Keep it dry after

Drying a PETG spool once is not the end. PETG re-absorbs moisture as soon as it sits open, so store it sealed with desiccant. Print it from a dryer on long jobs, since a warmed chamber keeps the moisture out through the whole run. A small hygrometer in the storage bin tells you when the desiccant is spent.

For the material background, the PETG hub covers the filament, and the filament storage guide covers keeping a dry spool dry.