Does 3D Printer Filament Expire?

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Are you finally getting around to firing up that 3D printer again, but it’s been a long time? You have the 3D printer filament in your hand and you start wondering – Does 3D printer filament expire? 

Yes, 3D printer filament does expire. Printing filament will eventually go bad. Moisture in the air is the main culprit that will shorten how long your filament is usable. On the flipside, there are also steps you can take to lengthen how long your 3D printing filament lasts. We’ll look at what you can do to keep your 3D printer filament fresh.    

Continue reading below for signs that the filament is weak and what you can do about it, if anything at all. 

Does 3D Printer Filament Expire?

It’s true what they say – nothing lasts forever, especially not 3D printing filament.

When you use expired 3D printing filament in your projects, you may end up with some results that you’ve never experienced before. Not in a good way either. 

This can be absolutely frustrating because in 3D printing you won’t be able to see or stop and problems mid-print. That means you would’ve wasted a heck of a lot of time if your project takes more than a couple of hours to finish. Especially when it comes to creating those 3D model files.

That’s time that could’ve been invested into something more productive, rather than a brittle print.

Does 3D printer filament expire

What Causes 3D Printer Filament to Expire and Go Bad?

There’s a wide variety of filament out there, but we’re only going to focus on the Top 3 filament types: PLA, ABS, and PETG. 

We’ll see if we can find common signs of expired filament along with causes for why 3D printer filament goes bad. We’ll also cover some proper storage solutions at the end. 


One of the most common reasons that explains why 3D printer filaments become so brittle is because of the absorption of moisture by the material in it. 

Storing your filament in high humidity areas will alter its physical properties quicker than usual and shorten a filament’s shelf life. 

It’s a problem when your 3D printer filament starts getting brittle and is more prone to breakage. Materials degenerate over time, and even more so when not stored properly. 

In most cases, it is usually the outermost part of your filament reel that starts to get brittle as this is the first surface area to get the most exposure to moisture in the air. 

If you feel like your prints are becoming more prone to breakage, then maybe it’s time to rethink the storage solutions of your filament spools before it’s too late.

PLA – Polylactic Acid

When PLA filament has expired, it’s generally because it’s absorbed too much moisture from its environment. 

What does PLA look like when it’s absorbed too much moisture? Unfortunately, there’s no clear way to tell unless you start printing with it. 

Unlike fresh PLA filament that’s corn-based, expired PLA becomes brittle and breaks with very little force. 

Storing PLA in an environment that has ample exposure to moisture and heat will cause it to go bad sooner than expected. PLA is not exactly water soluble, but it is known to have a very high water absorbent rate.

When it absorbs water, it swells up – increasing the risk of extruders not working and destroying the hot end of your 3D printer nozzle. 

During printing, you’ll also likely hear sizzling noises and pops coming out from the hot end resulting from the excessive amount of steam released by the moisture-rich material.

Not only that – with the added moisture trapped in the filament, this moisture turns to steam due to the heat from the nozzle, and results in inconsistent surfaces like gaps and bubbles on the printed object. 

ABS – Acrylonitrile Butadiene Styrene

The easiest way to tell if ABS filament has gone bad is to look at its color. What was once a vibrant, bright color will turn dull and faded, yellowish-brown. 

Unfortunately, this is something you’ll only find out after printing and over a period of time.

When you keep colored ABS filament exposed to moisture for too long, little hairline spots will start to form on the material. 

During printing, hairline gaps will occur between print layers and these gaps provide spaces for mold and bacteria to thrive, resulting in highly separated print layers over time. 

PETG – Polyethylene Terephthalate Glycol-modified

PETG is interesting because it’s designed to be less sensitive and last way longer than other filament types. There’s no surefire way to tell if PETG has expired just by looking at it.

Even when leaving PETG out in the open consistently exposed to humidity, PETG can still be usable up to about a year. However, it’s always best to store it in an airtight container with a desiccant to keep it bone dry.

Can You Print With Old Filament?

Of course you can! But with necessary caution and some extra steps in order to get the best print quality possible, otherwise you’d end up with brittle prints. 

If you have old filament, you would have to preheat, and then dry it before it’s safe to use. Otherwise, you might just end up with problems that might cause your entire 3D printer system to shut down altogether, like blockages on the nozzle and air bubbles, etc. That can turn costly to fix and time-consuming.

When using old filament, you also have to ensure that you don’t expose it further to air and the environment when not printing, or you’ll end up with completely unusable filament.

Another thing to note when you are printing with old filament – ensure that the print temperature is never set to be close to the filament’s glass transition heat.

So, the answer is yes, you can print with old filament. But do you really want to? Especially if you plan to make money with 3D printing.

How to Prevent 3D Printer Filament from Expiring

If you wish to keep your 3D printer filament in tip-top condition for the rest of its remaining shelf life, there are things you can do to prevent this unfortunate situation from landing in your lap.

Store Filament Properly

At the risk of sounding patronizing, we’re here to tell you that – if you want your filament to last longer (and thus save you more money), keep the filament away from moisture. 

Store the 3D printer filament in airtight containers and use a desiccant to absorb any and all moisture that leaks and seeps into the container (silica packets are great for this situation). 

Keeping your filaments as dry and moisture-free as possible to prevent them from degrading as quickly as when they are exposed to the humidity and the elements in the outside environment.


Don’t Buy More Than You Need

Another simple way to avoid expired filament is to not have the extra filament lying around in the first place. 

Retail shops and 3D printer filament distributors keep their stock in extra-secure facilities. They have the resources to do so and keep their filament stock ready to sell. They need their stock to be top quality for their customers, who are people just like you.

Only buy what you need for a particular project you’re embarking on. If you run out of filament, you’ll be comforted in the knowledge that you can easily get another spool at the local shop or online that is of the highest quality, kept in the best conditions.

3D printing is an enjoyable hobby, and one that many people take seriously and rightfully so, as the investment is a fairly large one.

It always helps to find ways to save every penny in order to invest it back into higher quality gear. If you don’t keep your filament in the right conditions to prevent premature expiration, you might just end up cutting corners in your projects.

And any shortcuts you take when 3D printing objects can and will show up as major issues on the final product.

If you’re looking for 3D printer filament, you can always check on Amazon as well.

Here’s a video of another 5 ways to ruin your filament.

5 ways to ruin your filament (and how to fix it)!

Photo Credit: “3D printing filament” by westonhighschooollibrary is licensed under CC BY-ND 2.0

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Written by:

Michael Hoyt
Michael Hoyt, a seasoned expert in smart home technology and robot vacuum specialist, is renowned for his contributions to home automation. With a deep-seated knowledge of smart devices, he has dedicated his career to enhancing living spaces with advanced technology. Michael's expertise extends from in-depth reviews and recommendations to practical advice on fully automating homes with smart home solutions.