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

Filament can be left inside a printer for very short periods, for example overnight. Leaving filament over longer periods like days or even weeks can damage the filament through exposure to humidity.

In simple terms, you can leave the filament in the printer for short spells, but you don’t want to leave it too long. But why would you want to leave your filament inside as opposed to packing it neatly away?

Depending on the scale and complexity of your design, 3D printing can take anywhere from 30 minutes to several days. A simple print can be done in one sitting whereas with something more complex you may need to spread it out over several sittings.

This can make things a little tricky when managing your printer and of course your filament. What do you do between prints? Should you remove your filament every single time, even when you’re working with a build that may take several days?

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).

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


In this article, we explore some of the questions related to managing designs that stretch out over lengthy periods. Can you leave filament in the extruder and what happens if you leave a 3D printer running overnight?

We will also look specifically at how to handle PLA filament when making a print that may take longer than usual. Do you need to store it or can you leave it out?

Can You Leave Filament In Extruder?

Filament can be left inside an extruder for short periods. This will not damage the printer or affect the print. However, it is advisable to remove the filament if a lengthy spell of inactivity or non-use of the printer is anticipated.

The biggest worry with leaving filament inside a printer is humidity. Humid conditions introduce the possibility of your filaments absorbing ambient moisture. Thermoplastics are hygroscopic. This means they readily absorb moisture when exposed to it. Source

Leaving filament inside a printer or extruder for long periods will likely result in moisture absorption. Filament that is saturated with moisture has several drawbacks.

  1. The filament may become unusable.
  2. It spoils the print and produces models that have cracks, holes, or bubbles.
  3. It can cause malfunctions in the printer itself. Nozzle jamming is a frequent occurrence caused by moisture in the filament.

It’s for these reasons that where possible, you should remove and store your filament if you anticipate you will not be using your printer for a while. For shorter periods this may not be necessary.

It largely depends on the type of filament you’re working with. Certain types of filaments are more moisture-absorbent than others. Generally, PVA, Polycarbonate, ABS, and Nylon are more hygroscopic compared to PLA, ASA, and Polypropylene.

Nylon, for example, can become saturated in a matter of hours, hence the need to remove and store it.

There are cases where it would not be practical to remove filament. For example, if you’re printing and have to stop for the night it would be impractical and tedious to have to remove the filament if you know you’re going to be printing the next day.

We should however stress that whether you remove filament or leave it will depend on the type of filament and the environment you’re working in.

If you’re in a humid environment and you’re working with a more hygroscopic filament, the safest option is to remove it.

We also highly recommend that you check out our post “Can 3D Printing Filament Go Bad? How Can You Tell & Deal With It!

Is It OK To Leave A 3D Printer On Overnight?

Leaving a 3D printer on overnight is not advisable. The main risk is a malfunction that can lead to a fire while the machine is unattended. Any number of things can happen while a printer is in use. The filament can jam and cause the machine to overheat for example. This can damage the machine, waste filament, or in extreme cases, result in a fire.

It can be tempting to leave a printer running overnight or while you’re away, especially when you have a long print that could take hours. Most printer manufacturers advise against this, however. There are a couple of things that could go wrong while you’re not looking.

The biggest risk is a printer malfunction leading to an electrical fire. Aside from this, there’s also the possibility your print will go wrong. One way this might happen is if your print detaches from the print surface.

In this scenario, you would want to be there to immediately stop the print if you want to avoid wasting material.

If, however, you have to use your printer overnight there are a few things you can do to reduce the risks.

  1. Use the machine auto shutdown function if the printer has one.
  2. Monitor the machine with a camera.
  3. Periodically check-in.
  4. Activate the thermal runaway protection. Some machines have it on by default. Others require you to turn them on. Thermal runaway shuts the machine down if there is any unusual behavior detected.
  5. Use an enclosure to house the printer. This cuts it off from surrounding objects which may be flammable.
  6. Print slower at cooler temperatures.

How Long Can PLA Filament Be Left Out?

PLA filament can go bad if left out for too long. Depending on the conditions under which it is stored, PLA can last for anywhere between days to 15 years before it becomes unusable. The determining agents that will affect the usability of the filament are humidity and light.

Both humidity and light degrade plastic. Exposure to either or both will shorten the lifespan of your filament. Direct sunlight on unsealed PLA can make it brittle to use within a week. This brings storage into play. How PLA is stored has a direct bearing on how long it lasts.

Does PLA Need To Be Stored?

All filaments perform better and have a longer shelf life when they’re kept in proper storage. PLA filament can last up to 15 years and remain usable throughout if kept in sealed containment that is free from moisture and UV light.

Filament that has not been stored properly will produce inferior prints. This is generally observable as cracks or bubbles in the finished prints. Proper storage ensures better quality prints.

The cheapest way to store filament is to use vacuum bags or Ziploc bags. Even food containers will do. As an extra precaution, you should also put silica gel in the container. The silica gel packs are drying agents which absorb moisture.

Another storage option for PLA is to use dry boxes. A dry box is a container specially made for storing and using filament. The advantage of a dry box is you can use the filament without taking it out of the dry box.

Check out our recommended storage case (Amazon link)

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


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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