PLA vs PETG vs ABS/ASA: which material should you pick?

PLA, PETG or ABS/ASA: the short answer

PLA is the standard choice for decoration, enclosures and anything that stays at room temperature indoors. PETG is what you choose for functional parts that have to bend rather than break, or that get damp and lukewarm. ABS and ASA are for heat up to about 85 to 100 °C, and ASA also for years of use outdoors.

If you are torn between two, choose on the basis of the highest temperature the part will ever see. A part that spends one summer's day behind a car window needs ASA that day, even if it lives in a cool garage for the rest of the year.

Comparison table

The table compares PLA, PETG, ABS and ASA on stiffness, toughness and heat resistance, using the figures manufacturer Bambu Lab states for its own filament. PLA is the stiffest (2,360 MPa), ASA resists heat best (100 °C) and is the toughest under impact (41 kJ/m²).

Source for the figures: Bambu Lab's technical data sheets for PLA Matte, PETG HF, ABS and ASA. They are the manufacturer's values for that one filament, measured on solid test bars in the strongest direction (ISO 178, ISO 179 and ISO 75). A real print with an open infill does not reach them. Use them to compare materials with each other, not to calculate what a part can carry. The rows without a figure are general rules of thumb, not measurements.

When to choose PLA

Choose PLA for anything that has to look good and does not get warm: decoration, name signs, scale models, prototypes, organisers and holders for indoors. PLA is the stiffest of the four, gives the crispest detail and comes in the most colours. It does soften from about 58 °C.

Yannic Fréson 3D has thirteen colours of PLA in stock and prints up to four per object. PLA is also the cheapest material and prints the fastest, so if your part will not face heat, sun or heavy knocks, there is little reason to choose anything else. The properties and colours are on the materials page. No PLA print here is suitable for contact with food.

When to choose PETG

Choose PETG for parts that have a job to do: clips, knobs, hinges, brackets, enclosures and anything in a bathroom, cellar or garden shed. PETG is tougher than PLA: it bends or tears where PLA snaps. It also takes about 10 °C more heat, up to 69 °C according to the manufacturer.

Is PETG stronger than PLA, then? That depends on what you call strong. PLA is stiffer: it deflects less under the same load. PETG is tougher: it absorbs a knock better, with an impact strength of 31.5 against 19.2 kJ/m². You want a bookend stiff; you want a clip you will click open a hundred times tough. Whatever the material, a print is weaker between its layers than along them, so the print orientation matters as well.

When to choose ABS or ASA

Choose ABS or ASA when a part gets warmer than 60 to 70 °C or has to stay outdoors for years. According to the manufacturer, ABS stays dimensionally stable up to 87 °C and ASA up to 100 °C. The difference between the two is sunlight: ASA is made to withstand UV and weather, while ordinary ABS yellows and turns brittle sooner outdoors.

Both materials are harder to print. They shrink as they cool and warp as a result, especially on large flat parts. That is why they are printed in an enclosed printer with a warm chamber: Bambu Lab recommends a print bed of 80 to 100 °C and a chamber temperature of 45 to 60 °C. That extra risk explains the higher price. ABS and ASA are not in stock and are ordered on request. More on the materials page.

Which material for outdoors?

For outdoors, choose ASA. It is the only one of the four materials that the manufacturer itself recommends for long-term use in sun and rain, and it stays dimensionally stable up to 100 °C. PETG is a reasonable alternative for a part in the shade. PLA is not a material for outdoors.

PLA survives a shower perfectly well. The problem is the sun: a dark part in full sun easily gets warmer than 58 °C and then slowly sags. After a few seasons PLA also becomes more brittle and paler. A PLA planter on a shaded terrace will last a while. A bracket for a south-facing letterbox will not.

Which material in the car or near heat?

In the car, choose ASA, or ABS for a part that never sees the sun. Behind a car window on a summer's day the temperature climbs higher than the 58 °C at which PLA softens, and PETG with its 69 °C is at its limit then too. ASA holds up to 100 °C.

Good to know. The HDT, or heat deflection temperature, is the temperature at which a test bar under a small load starts to bend. It is not a safe service temperature. A part under tension, such as a clamp or a spring, deforms a good deal lower. For a part like that, allow a generous margin.

Parts near an engine, an exhaust, a heating element or a lamp that gets hot are beyond what these plastics can handle.

What is the difference in price?

PLA is the cheapest, PETG costs a little more and ABS and ASA are the most expensive. The difference lies less in the spool of filament, which costs from about €23 per kilogram for the four materials, than in the printing itself: PETG and especially ABS and ASA fail more often and need more preparation.

The spool prices: PLA, PETG HF and ABS each cost from €22.99 per kilogram in the Bambu Lab EU store, and ASA costs €25.41 at the Dutch reseller Makerpoint.

For a small part you hardly notice the difference, because the minimum order of €10 then sets the price. On large parts it adds up. The rates per material are on the pricing page, and how they turn into a quote is in the guide on what 3D printing costs in Belgium.

And matte, silk or wood-filled PLA?

Matte, silk and wood-filled are three finishes of the same material: PLA. Matte PLA hides the layer lines best. Silk shines like polished metal. Wood-filled PLA contains fine wood powder and feels and looks like wood. Heat resistance stays at around 58 to 60 °C for all three.

According to Bambu Lab's data sheet, wood-filled PLA is slightly stiffer than matte PLA (2,780 MPa), but weaker between the layers. It is a material for the eye, not for strength. Silk shows layer lines and seams just a little more, because gloss shows everything. It is the dinner jacket among filaments: splendid, as long as you do not have to work in it.

Want it printed?

Whether you know which material you need or have no idea: say where the part will go and what it has to do, and the quote will propose the material. Read more about having a replacement part made or request your quote.