PA (nylon) vs PETG — parameter comparison and when to choose which

The decision in one sentence: nylon is not a filament but a process — if you do not have a heated chamber and cannot keep up 8–12 h of drying at 65–80 °C before every print, PETG will give you a better part, even though it looks weaker in the table.

In the manufacturer Porima's official FDM table, PA carries one value nobody else in the catalogue has: 150 °C of temperature resistance. It also has the only entry in the whole table where the manufacturer has added the word "required" — against drying. Those two things have to be read together. Nylon is a material where the outcome is decided not by the slicer profile but by the discipline around the print: preparing the filament, the chamber, and what happens to the spool between one job and the next.

Comparison table

Parameter	PA (nylon)	PETG
Nozzle temperature	260–290 °C	240–260 °C
Bed temperature	90–120 °C	60–80 °C
Cooling	30–100%, first 5 layers off	100%
Drying	8–12 h / 65–80 °C — required	2–4 h / 30–40 °C
Chamber enclosure	enclosed and heated	open frame
Temperature resistance	150 °C	85 °C
Print difficulty	very difficult	easy
Warping	medium	none
Stringing	low	high
Layer cohesion	very good	very good
Impact resistance	high	high
Flexibility	high	high
Surface finishing	easy	medium
Support removal	easy	medium
Odour	medium	very low
Nozzle abrasiveness	moderate	none
Print speed	high	high
Colour saturation	medium	high
Finish	smooth, opaque	glossy, translucent
Compatible printers	enclosed, with a heated chamber	any desktop FDM
Bambu AMS	not compatible	compatible

A highlighted cell marks the material that is clearly better in that row. Where the values are equal we name no winner. Source: the official FDM technical data table from the manufacturer, Porima. Full data sets: PA (nylon) print parameters · PETG print parameters.

When to choose PA (nylon)

Gears, drives and parts working in friction. This is the most common use of nylon in 3D printing and the only one where the difference from PETG is obvious from the first day of service.

Parts working above 100 °C. A declared 150 °C is the highest value in the whole Porima catalogue — higher than ABS, ASA, PC/ABS and HT PETG.

Living hinges and parts flexed cyclically. Layer cohesion "very good" plus flexibility "high" — nylon takes repeated bending where other materials crack after a few dozen cycles.

Brackets and fixings near motors and heaters. Places where PETG is already out after the device's first summer day of running.

Parts intended to be sanded and finished. Surface finishing "easy" and support removal "easy" — nylon is more pleasant to work than PETG.

When to choose PETG

Anything below 85 °C, which is the vast majority of jobs. Housings, supports, guards, brackets. PETG handles those on an open machine, with no drying ritual.

Parts that have to be a particular colour. Colour saturation "high" against "medium" for PA. Nylon is naturally pale and it shows.

Large flat parts. Warping "none" against "medium". With nylon you also have to hold an even chamber temperature for the whole print.

Production from an AMS. PA is marked as not compatible, PETG as compatible. In serial work that is an organisational difference, not a cosmetic one.

Anything you print only occasionally. A spool of PETG left in a cupboard for a month will still print a sound part. A spool of nylon in the same conditions needs a full drying cycle before you even go near the machine.

What the table won't tell you

"Drying required" is the only entry of its kind in the whole table, and it is not a recommendation. Nylon without drying does not print worse — it does not print properly at all. Crackling in the nozzle, bubbles, a porous surface and layers that do not hold on to each other. Eight to twelve hours at 65–80 °C is not something you shorten when you are in a hurry.

Nylon takes up moisture during the print as well. A dried spool left out in the air returns to its original state faster than a long print takes. In practice that means feeding the filament from a dry box or from a dryer running continuously — otherwise the first half of the model will come out differently from the second. That row is not in the table, and it decides the outcome more than all the temperatures put together.

"Enclosure closed and heated" means exactly what it says. An enclosed case that merely warms itself up from the bed is not enough — PA is the only entry in the table that requires an actively heated chamber. Most workshops do not have such a machine, and that is the real reason nylon stays in the catalogue rather than on the bench.

150 °C is the manufacturer's label, not HDT. There is no standard or described test method behind it, and it is not the temperature at which the part will carry a load. With a value this high the temptation to over-read it is greatest, so to repeat: it orders the catalogue, it does not replace a test on the finished part.

"Nozzle abrasiveness: moderate" means brass wear, not immediate failure. Nylon does not demand a hardened nozzle as absolutely as carbon-fibre materials do, but with regular use the nozzle diameter slowly grows and dimensions start drifting. It is worth checking before you start looking for the fault in the model.

The "first 5 layers without cooling" entry is the setting most often forgotten. In most slicers that is a separate field and does not follow automatically from the material profile. If the first layers of nylon are lifting off the bed, start by checking exactly that.

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.
• PA (nylon) print parameters — the complete set of fields from the manufacturer's table.
• PETG print parameters — the same for PETG.
• Wet filament — with nylon, required reading before the first print.
• Warping — nylon curls differently from ABS and needs a stable chamber.
• Layer separation — the first symptom of under-dried PA.
• Stringing — a problem on the PETG side, not nylon's.

Materials to buy: Porima PA filament 1 kg (nylon) and Porima PETG filament 1 kg.