Best 3D Printing Filament for Outdoor Use: Is PLA Suitable?

3D printing is amazing for functional objects whether inside or outside. There are some changes that you’ll want to make if you plan to 3D print something for outdoor use, and that main thing is the filament type.

This article will outline some of the best filament that people use for the outdoors.

The best filament for outdoor use is ASA because it has great protection against outdoor environmental factors such as rain, heat from the sun & UV rays that can easily affect other types of filament. Most filament works out fine, but it can discolor or get weaker over time.

There are definitely other contenders and great options that you can choose from when it comes to using filament outdoor, so stick around and read some useful information about the best filament for outdoor use.

What is the Best Filament for Outdoor Use?

The best filament for outdoor use is something that doesn’t deteriorate due to wind, sun (UV rays), heat and rain. Two amazing filament types that have very high resistance to all of these environmental factors is ASA & PETG.

ASA

ASA is basically an upgraded version of ABS, where ABS can easily discolor from UV rays, ASA has protection against it. You won’t find ASA starting to melt under higher temperatures, becoming brittle and weak due to water, losing strength and color from the sun or being heavily affected by wind.

It’s a highly-resistant material which is considered the best filament for outdoor use. Price-wise, it isn’t too expensive to get your hands on some good quality ASA, so if you have a project that requires printed parts to be outdoor, definitely make use of this.

The main downside of ASA though, is the difficulty in getting it to print successfully. Depending on your 3D printer and experience, it could be easy to get the hang of, or it could be a troublesome, but with some guidance you should be just fine.

Some great ASA filament you can get from Amazon is the SUNLU ASA 1.75mm 1KG Filament. It has a really good dimensional tolerance of +/- 0.2mm, is tangle-free, clog-free, and bubble-free.

You’re getting great weather resistance and UV resistance with this filament.

PETG

PETG is kind of like the hybrid upgrade of PLA & ABS, since it does so many things right. The first thing people love about PETG is how strong it is, being able to keep up with ABS for the most part and also being easy to print.

When it comes to using PETG for outdoor use, it’s an easy choice to make, mainly due to it’s UV resistance and ability to keep strength over long periods of time.

Over time, you might find some discoloration depending on the filament quality and color, but it should be fine in most other aspects. PETG is quite sensitive to moisture so you should try to store it adequately when it’s not in use.

One very popular brand of PETG is the OVERTURE Clear PETG 1KG Filament from Amazon. It has gone through over 8 years of research and development, fine-tuned to get it perfect for each customer.

It’s mechanically-wound to give you a smooth, tangle-free 3D printing experience.

Polycarbonate

The natural UV-resistant characteristics make polycarbonate a good candidate for a suitable filament for the outdoors. It’s commonly known as one of the strongest 3D printer materials out there and can definitely hold up in extreme situations.

It’s definitely stronger than PLA & ABS while having a great amount of mechanical endurance, so any kind of functional print which has high load-bearings can easily rely on polycarbonate to get the job done.

The main thing to remember though is just how difficult it is to print with compared to your more common filament. It’s going to take a well-tuned 3D printer, some guidance and some trial and error to get your prints coming out perfect.

Polycarbonate is sometimes fairly pricey, but would work well for your outdoor project.

There is actually a brand of Polycarbonate which has really decreased its price, sold by HZS3TD. Check out the Transparent Polycarbonate 1KG Filament on Amazon, which can withstand temperatures of 110°C.

TPU

TPU is your unique, flexible filament that has many uses and it can be used safety in sunlight and other outdoor conditions. When it comes to functionality, this material does very well because of it’s rubber-like properties and resilience to external factors.

Similar to polycarbonate, TPU can be quite difficult to print and you need a certain level of extruder to print it to a good standard. All-metal, double-geared extruders work very well to print flexible filament like TPE, so think about upgrading if you want to implement it.

It’s always a good idea expanding your 3D printing limitations and it can also lead to better quality with your other printing projects.

Tronxy Flexible TPU 1.75mm Filament from Amazon is a great choice for a filament to use outdoors. Even though it’s flexible, it is also tough at the same time. It can be quite difficult to print with, and you’ll have better chances using a direct drive extruder.

ABS

I think the most useful characteristic of ABS is how high it’s heat-resistance is compared to other materials. Since it requires a higher temperature to print with, it translates to being able to withstand higher temperatures, such as being in a hot car.

In terms of the UV damage that affects 3D printing materials, it does get affected by the UV rays but not as much as PLA. The durability of ABS works very well in outdoor settings, so if the part isn’t load-bearing, it should work just fine especially if it’s not in the sun for too long.

ABS can be made weaker from UV light so keep that in mind when choosing this material for outdoor use.

You’ll likely over a long period of time get some discoloration which can be made worse from direct sunlight.

If you want to go with the ABS option, I’d recommend the HATCHBOX ABS 1KG Filament from Amazon.

How Do I Make 3D Prints Suitable for Outdoors?

Use an after-care product like a UV-resistant coating which can prevent degradation from sunlight. These products can easily be found on Amazon and are used by tons of 3D printer users to boost the functionality of their 3D prints.

Rather than opt-in for using ASA, you can definitely choose to use ABS along with a UV-resistant coating to last you a long time. It’s not difficult to do at all, and is as simple as using a paint brush to coat your print.

Using a reflective coating not only helps with sun rays but also reduces heat effects to your models.

In order to help with UV-resistance, it is a good idea to 3D print with a darker material, ideally black because the pigments give you some extra UV protection.

Is PLA Filament Suitable For Outside/Outdoors?

PLA

I would be concerned using PLA filament in an outdoor environment, especially if it has load-bearing functionality meaning it has weight and movement applied to it. That’s not to say it won’t work and do a great job for some time, but gradually it will get weaker.

A mixture of the rain, sunlight, heat and other environmental factors can weaken PLA to a point where it won’t be very suitable for the outdoors.

If we are talking about a purely aesthetic piece which is protected against rain, it is a feasible idea, but in other cases you might want to opt-in for a different material.

PLA is the most popular 3D printing material used today but it doesn’t make it the best material for certain circumstances.

The ease of printing of PLA partly comes down to its low printing temperature, so if the environmental is hot, your prints can actually start to melt. PLA is biodegradable, but it takes quite harsh conditions to do so, not at standard ambient conditions.

We also have to keep in mind the damage from UV light which can discolor, weaken and even disfigure PLA printed parts.

Keep in mind also that PLA is fairly hygroscopic so it will absorb moisture from the immediate environment, although many people have used PLA printed parts underwater for several months and things are still in order.

PLA is mostly intended to be used for indoor projects and purposes so if you are after the ideal recommendation for PLA, I wouldn’t use it outside, but PLA can be suitable for the outdoors in the right conditions.

When you do see actual projects that people have done where PLA is used outside, you generally don’t get massive complaints about its effectiveness.

One user mentioned that he has had PLA parts that have been out in the full sun and extreme weather outdoors for years and still going strong. They even have a decent part of their fence held together with PLA brackets.

PLA being unsuitable for the outdoors might just be the opinion on paper, but practically speaking, with thick walls, good infill and a well-tuned 3D printer, I’m sure PLA parts can be used outdoors for several years without issues.

On the other hand, we also have to keep in mind that not all PLA is the same, and we have several types of PLA that are a lot more durable and resistant than your standard PLA.

Using PLA+ or HTPLA is definitely a better option to be suitable for outdoor use.

How Long Will PLA Last Outside?

PLA can easily last several years outside depending on your environment, humidity, heat and levels of sun that affect it. If you happen to have the PLA under some protective shade which prevents rain and the sun from affecting it, then a PLA print should last very long outside.

If you are in a location which has some serious heatwaves, rains heavily and isn’t protected, you can definitely count on that PLA model deteriorating fairly quickly.

So with the right knowledge, your PLA can last a good amount of time in the outdoors. I would also keep in mind whether there is going to be physical pressure or a constant load on the PLA.

For example, I probably wouldn’t use PLA for something like a hand rake or shovel for the garden unless you don’t mind printing another one in the future.

It really does depend on the quality of PLA you are using as well, as one user 3D printed a handle on the side of the door that was outside, and despite constant sunlight and weather, lasted 3 years, but this was in Germany which doesn’t get too hot.

The UV isn’t the main problem, it’s more so the heat. If you live in a hot location that has scorching heat in the summers, PLA won’t hold up very well.

Somet people have left PLA outside for over 5 years and it hasn’t broken down, so it keeps its structural integrity pretty well under normal weathering.

How Long Will PLA Last in Water?

If you’re wondering how long PLA lasts in water it’s hard to put it down to a specific time frame because there are different conditions that can occur.

According to HowStuffWorks:

PLA decomposes into water and carbon dioxide in 47 to 90 days, four times faster than a PET-based bag floating in the ocean. Plastics like PLA need conditions to be just right to achieve those results.

The proper way to break down PLA plastic is to use a composting facility which puts the plastic into an environment of high temperature. Burying PLA into a landfill may not really break it down so quickly, probably lasting as long as a normal plastic bag.

PLA isn’t soluble in water, but it does have a large tendency to absorb it in the environmental, mainly the humidity.

Many people have put the water submersion test to practice and the results are interesting. Although PLA absorbs water in the environment, it only can soak up a certain percentage of water, where one study found a 1-6% increase in weight after 30 days.

One user accidentally left a PLA print in a jar of water for 3.5 years and what he found out was, there actually wasn’t much of a difference at all, and said ‘it looks and feels like the day it came off the printer.

The difference with PLA and water is depending on what other elements are in that water, such as microscopic critters in ocean water. Another person put a PLA print in a salt water aquarium for over a year and it’s still going strong.