PLA vs PETG — parameter comparison and when to choose which

The decision in one sentence: if the finished part has to work in heat or take knocks, you take PETG; if what matters is accuracy, a clean print and no trouble on the first attempt, you take PLA.

This is the most argued-over question in 3D printing, and it usually gets answered with the sentence "PETG is better". It isn't. The manufacturer Porima's official FDM table has the same thirty fields filled in for both materials, and once you line them up something else becomes clear: PLA and PETG differ in literally a handful of places, but those few places decide everything. Below they are set out row by row, with nothing glossed over.

Comparison table

Parameter	PLA	PETG
Nozzle temperature	200–230 °C	240–260 °C
Bed temperature	0–60 °C	60–80 °C
Cooling	100%	100%
Drying	2–4 h / 30–40 °C	2–4 h / 30–40 °C
Chamber enclosure	open frame	open frame
Temperature resistance	60 °C	85 °C
Print difficulty	very easy	easy
Warping	none	none
Stringing	low	high
Layer cohesion	good	very good
Impact resistance	high	high
Flexibility	low	high
Surface finishing	easy	medium
Support removal	easy	medium
Odour	none	very low
Nozzle abrasiveness	none	none
Print speed	high	high
Finish	smooth, opaque	glossy, translucent
Bambu AMS	compatible	compatible

A highlighted cell marks the material that is clearly better in that row. Where the values are identical there is no winner, and we do not pretend there is. Source: the official FDM technical data table from the manufacturer, Porima. Full data sets: PLA print parameters · PETG print parameters.

When to choose PLA

Display models, mock-ups and anything meant to look good on a shelf. The finish is smooth, colour saturation is high, surface finishing is easy. PETG is glossy and scatters light, so fine detail gets lost — PLA shows it.

Dimensional prototypes you check and then throw away. Zero warping, no enclosure, and you can leave the bed unheated altogether (range 0–60 °C). If you hit the dimension first time, it is usually on PLA.

Toys, figurines, gifts, things printed with children around. Odour is listed as "none" — the only such material in the table alongside TPU. The printer can stand in the living room.

Parts with supports and complicated geometry. Support removal being "easy" for PLA and "medium" for PETG is a difference your fingers feel after twenty minutes of picking at a model.

Long, many-hour prints on an unattended machine. The "very easy" difficulty rating is not marketing, it is a description of how many things can go wrong.

When to choose PETG

Anything that stays in the car. A phone holder, a glovebox organiser, a cable grommet. In summer the dashboard of a parked car goes past 60 °C and a PLA part simply droops like overcooked pasta. PETG has a declared 85 °C.

Enclosures for electronics, power supplies, controllers. Anything that heats up from the inside and has to sit switched on for weeks.

Brackets, clips, hinges and parts that work in bending. Flexibility "high" plus layer cohesion "very good" — PETG gives instead of splitting along a layer. PLA snaps here.

The workshop: guards, guides, cover plates, parts that live near tools. PETG forgives a knock and does not go brittle with age.

Translucent parts — LED diffusers, covers, level sight glasses. PLA will not do this, because the table says plainly "opaque".

What the table won't tell you

Impact resistance reads "high" in both rows, and that is exactly the point where the manufacturer's data ends. There is no standardised impact test behind it, so it is a description, not a measurement. The practical difference is not in the value but in the way the part fails: PLA cracks suddenly and right through, PETG deforms first and turns white. For a part that is meant to warn you it is overloaded, you will choose PETG — even though the table rates the two materials equally.

60 °C and 85 °C are the manufacturer's labels, not HDT. There is no standard or test method behind them, and they do not mean the part will carry a load at that temperature. Treat them as the point above which the material starts behaving differently — not as a guarantee. If the part is a responsible one, print it and heat-soak it for real in the place it is going to work.

"High" stringing on PETG is not a bad batch. It is a property of the material and the most common reason people bounce off PETG after the first spool. You solve it by drying, dropping the nozzle by 5 °C and lengthening retraction — not by changing supplier. Zero stringing has to be reached through settings; the table will not do it for you.

Drying has an identical row, and different behaviour. Both materials are dried for 2–4 h at 30–40 °C, but PETG announces moisture far faster and far more clearly: it crackles in the nozzle and leaves a haze on the surface. PLA can take on water and merely go dull, so the problem slips past you.

"High" speed in both rows refers to the material, not to your printer. At high speeds PETG needs more time to cool bridges and overhangs, so the real print time for the same model can be longer, even though both entries in the table look the same.

Where to check this further

• Filament comparison — which material to choose for what — the hub for all ten pair comparisons plus the main table of twelve material families.
• PLA print parameters — the full set of fields from the manufacturer's table.
• PETG print parameters — the same for PETG, together with the bed range.
• Stringing — required reading before your first spool of PETG.
• Wet filament — crackling, haze and a dull surface.
• Layer separation — this is where the difference in layer cohesion between PLA and PETG shows.
• The first layer won't stick — PETG likes to stick too well, PLA not well enough.

Materials to buy: Porima PLA filament 1 kg and Porima PETG filament 1 kg.