PLA vs PETG: which filament should you choose?

PLA vs PETG: which filament should you choose?

PLA and PETG are two of the most popular filament types for 3D printing. Both are amongst the easiest materials to print with, are affordable, and together cover a surprisingly large share of what most people actually need to 3D print.

So which one is right for you?

PLA: simple, rigid, and based on renewable raw materials

PLA (polylactic acid) differs from many other plastics in that the PLA raw material itself is made from renewable resources, usually sugar or starch from plants such as wheat, rather than petroleum.

PLA is biodegradable, but degradation happens much faster under proper industrial conditions than outdoors in nature, where it can take a very long time. Finished filament also often contains pigments and other additives, such as PBAT.

PLA is easy to print, shrinks little, and produces fine detail. It is therefore a very good material for, among other things:

• Prototypes and product development

• Decorations and models

• Most ordinary indoor projects

For development work, PLA is especially practical. You can quickly print and test several versions of a part without using a more demanding technical material before the design is actually finished. At the same time, the main raw material is renewable, and the material is well suited to recycling when the waste is kept sorted.

The main limitation is that PLA does not tolerate heat and prolonged exposure to weather and sunlight as well as some more robust filament types.

PETG: the workhorse for functional parts

PETG is a petroleum-based plastic and is generally tougher and more impact-resistant than PLA. It also tolerates higher temperatures, moisture, and weather better.

This has made PETG a very common material for functional 3D-printed parts. Mounts, holders, enclosures, spare parts, prototypes, and other practical components can often be printed in PETG without needing more advanced materials. It is especially well suited when the part needs to withstand impact, water, moisture, outdoor use, or temperatures that become too high for ordinary PLA.

PETG normally has better resistance to moisture and UV exposure than PLA and can therefore be a better option for parts that will be used outdoors. For demanding or long-term outdoor use, there are still materials such as ASA that are better suited when UV and weather resistance are critical.

On the other hand, PETG can be more prone to stringing, while PLA is often easier to get looking very neat with fine details.

Many variants of the same polymer

Both PLA and PETG come in countless blends and specialty variants. CF (carbon fiber) can make the material stiffer, more dimensionally stable, and give a very neat matte surface, but can also make the part more brittle. HS (High Speed) is developed for faster printing and can in some formulations also produce a more flexible and less crack-prone material.

These are only two examples. Properties can vary a great deal between different blends of the same polymer.

What about recycling?

Both PLA and PETG are thermoplastics and can be remelted and used again. If you keep the material types sorted, failed prints, supports, and leftovers can become a valuable raw material instead of waste.

That is why Fjord3D has its own recycling program for 3D print waste. Our goal is to collect sorted material and reuse as much of it as possible.

PLA or PETG?

A simple rule of thumb for me is:

Choose PLA for prototypes, decorations, and most ordinary prints. Choose PETG when the part needs to withstand more heat, moisture, impact, or weather.

It is easy to assume that a functional part automatically requires nylon, carbon-fiber-reinforced filament, or other technical materials. In practice if often find this unnecessary. PLA and especially PETG cover a very large share of ordinary use cases, while also being easier and cheaper to print with.

So do not choose a more advanced filament just because it sounds better. Technical materials absolutely have their place, but only when the properties of the part actually require them.

The right filament is not the most advanced material. It is the simplest material that does the job well.

Recycling