How Long Can Filament Be Left Out? Tips On Storing & Using Leftovers!

Imagine starting work on a complex model using a new technique you have just learned. You’ve been itching to try it out and you have got your spool loaded and you’re about to start. But then the phone rings and it’s your boss saying you need to come to work right away.

Now you have a small problem on your hands. Do you rush to pack the filament away or can you just leave it in your printer? While you’re at work you’re probably going to be a little worried if you leave the filament out. But should you be?

How Long Does PLA Filament Last After Opening?

PLA filament can last up to three years after it’s been unsealed. In most cases, it can be used for much longer provided it is stored away from moisture or direct sunlight.

Storage is a critically important part of maintaining filament in good working condition. PLA that has been left out has a shorter shelf life and does not print as well as a filament that has been stored properly.

Check out our recommended storage case (Amazon link)

On a side note! If you’re looking for a reliable and high-quality 3D printer, we highly recommend the Official Creality Ender 3 V2 Upgraded 3D Printer (Amazon Link).

This printer is an upgraded version of the popular Ender 3 model, with a range of new features and improvements that make it even easier and more convenient to use.

The Ender 3 V2 is an excellent choice for beginners, kids, and experienced users.


OR for a budget option, You could go for a Cheap filament Storage Bag (Amazon Link)

Also, check out Can You Leave Filament In A 3D-Printer? How To Deal With It!

The filament can be left out for varying periods. It largely depends on two factors, chiefly the ambient environment in which the printer is operated and the type of filament used.

The environment

This relates to the humidity levels where you live and where you operate your printer. One of the most important characteristics of filament is how it behaves when it’s exposed to moisture.

Filament is hygroscopic. When exposed to moisture it absorbs the moisture. This negatively affects the filament, the printer, and the project you’re working on. Generally, the wet filament becomes weaker and brittle which leads to:

  1. Malfunction in the printer. While the filament melts, the moisture in the filament will bubble and steam. This can damage the printer itself.
  2. Poor prints. Prints made from moisture-saturated filament tend to be weaker and have several flaws. This might be cracks, streaks, or a rough texture on a print that should be smooth.

Moisture in the environment will likely be soaked up by your filament if you leave it out too long. This might not be a problem if you live in drier states like Nevada or Arizona.

If you live in more humid states like Alaska or Florida, you might want to consider taking steps to keep your filament dry. We examine a few of these steps later in the article.

The type of filament

Certain types of filaments absorb moisture at a faster rate. These include PVA, Polycarbonate, Nylon, and ABS. Nylon is especially hygroscopic with a faster absorption than most filaments. Nylon can become saturated in a matter of hours in very humid areas.

PLA, ASA, and Polypropylene have slower rates of absorption in comparison.

We also highly recommend that you check out our post “Does ABS Filament Absorb Moisture? How To Deal With It!

In combination, the humidity in your environment and the type of filament used will determine how long you can leave the filament out without worrying about it getting saturated. Source

Does PLA Filament Have A Shelf Life?

PLA has a shelf life of between 2 to 3 years. This, however, depends on how it is stored and the brand used. Some brands of PLA may have a longer or shorter lifespan. Ultimately, proper storage will extend the lifespan.

We highly recommend that you check out our post “Does PLA Have A Shelf Life? How long & How To Store It for A longer Shelf Life!

PLA has a similar shelf life to ABS filament. Both PLA and ABS are popular filament types used in the majority of print projects by both hobbyists and professionals. This is because the filaments are cheap and relatively easier to use compared to other filament types.

Nylon and PETG are also quite popular filament types. They, however, have shorter lifespans with Nylon having a shelf life of one year and PETG having a shelf life of two years. Source

Moisture and light are the two main concerns when it comes to the shelf life of the filament. Once filament absorbs moisture it becomes weaker and harder to use. Direct sunlight also has the same effect. These are both things you need to consider before you use a filament.

In some cases, even brand-new filament can have moisture in it if it wasn’t stored properly before it was shipped or if it was sitting on a shelf or a warehouse. How do you tell if your filament might be wet?

The best way to tell is to run the filament through the printer. If it starts to crackle or pop, then that is a definite sign the filament is wet and needs to be dried.

There are several ways to dry filament. The most popular methods are using a food dehydrator or oven drying. Those are the cheapest and most convenient methods since almost everyone has at least an oven!

A more sophisticated method is to use a filament dryer. These are boxes that use or have a heating mechanism to dry filament. While you can buy a dryer, DIY solutions work just as well.

How Do You Store Leftover Filaments?

There are several ways to store filament to ensure it does not get wet. The simplest is to use cheap vacuum-sealable bags. Combined with a drying agent like silica gel, these bags will keep filament moisture free and in prime condition for longer.

Check out our recommended storage case (Amazon link)

OR for a budget option, You could go for a Cheap filament Storage Bag (Amazon Link)

Dry boxes are similar to filament dryers except they do not have a heating mechanism. Like dryers, you can buy one or simply make a DIY dry box.

Aside from storage, there is also the option of recycling filament. This is especially useful when there isn’t enough filament left on the spool to start a new project. It would be a waste to throw it out so what do you do with it? Here are a few ideas:

Create tack-on pieces

These are small pieces you can use to join larger prints together. These might be pins or hinges in a moving model.

Create a composite

If you don’t need to create a high-fidelity print you can use a leftover filament to “make up the difference”. This might be the case where you have a print but you have run out of a particular color. If matching colors is not important you can use your left-over filament.


I am a very well experienced techie civil engineer who's extensively interested in 3D printing technology and even more captivated by the potential of 3D printing livable structures

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