PETG filament, ranked by £/kg

The sensible step up from PLA

PETG is tougher than PLA, holds up to around 75 °C, resists UV and moisture reasonably well outdoors, and — most usefully — bends before it breaks. For brackets, clips, enclosures, outdoor fittings and anything that gets handled, it is the obvious choice, and it does all this without needing an enclosure.

It is also chemically resistant and food-safe in the raw material sense, though a printed part’s layer lines harbour bacteria regardless of the polymer, so treat “food-safe filament” claims with care.

What it costs you

PETG is stringier than PLA, and the fix is fighting retraction and temperature rather than eliminating it entirely — expect some wisping and plan to clean up. Overhangs and bridges are less crisp. It absorbs moisture noticeably faster than PLA, which shows up as popping and rough surfaces within weeks in a damp room.

And it sticks to smooth PEI too well. This is not a minor point: PETG can bond hard enough to tear the coating off a build sheet. Use a glue stick as a release layer, or print on a textured plate — see build surfaces compared.

Settings to start from

Nozzle 230–250 °C, bed 70–80 °C, and reduce cooling to roughly 30–50%. This last point is the one people get wrong: PETG cooled aggressively looks tidier but bonds badly, which throws away the toughness you bought the material for.

If you are getting stringing, drop the nozzle temperature in 5 °C steps before increasing retraction, and check the filament is dry.

A standard brass nozzle is fine, and an enclosure is not needed — though if you have one, a closed door does no harm and slightly improves layer bonding on tall parts. Only the carbon-filled grades need hardened steel; see PETG-CF and hardened versus brass nozzles.

When PETG is the wrong choice

• Fine detail and crisp overhangs. Plain PLA prints sharper and cleaner, and for a display model there is no reason to use anything else. PLA versus PETG covers the trade properly.
• Above about 75 °C. Step up to ASA or ABS, accepting the enclosure and ventilation that come with them.
• Long-term sunlight. PETG copes with weather better than PLA but ASA is the material actually formulated for UV.
• Parts that must squash or grip. PETG bends; it does not stretch. That is TPU.
• Sliding or geared parts under load. Nylon is the wear-resistant, self-lubricating option.

Buying notes

PETG is generally a little more expensive per kilo than PLA, though the gap is often smaller than people assume — the ranking on this page is the place to check on any given day. Keep it dry: see filament storage.

How to read this table

The per-kilo column is the only number that compares listings honestly. A spool sold at 40% off can still be poor value, and a multi-spool bundle looks expensive until you divide by its total weight. We count bundles at their full weight, so a 4 × 1 kg pack and a single 1 kg spool sit on the same scale.

Where a listing does not state a usable weight we leave the per-kilo figure blank rather than guessing — a wrong ranking is worse than a missing one.