How to Store 3D Printing Filament




Introduction: How to Store 3D Printing Filament

About: Made in Canada, I grew up crafting, making, and baking. Out of this love for designing and creating, I pursued a BFA in product design from Parsons School of Design in NYC. Since then I've done work for Mart...

Whether you're a hobby 3D printer or someone who does it professionally, the most important thing to know – other than how to work the machine of course – is how to properly protect and store your 3D printing filament.

Filament that hasn't been properly stored absorbs moisture from the air, which over (not very much) time degrades its quality, causing failed prints, sputtering (as the stored moisture is heated going through the machine), and nozzle blockages (the WORST!).

In this instructable, I'm going to show you an inexpensive solution for this problem that will save you time (fewer nozzle cleanings!) and money, by protecting your filament investment (that stuff ain't cheap!).

Ok, let's go save a filament's day!

Step 1: Supplies

The list of things you need is nicely short – AND as I said, inexpensive.

NOTE: The silica packs are reusable many times over (by drying them out in the oven and re-activating them) and the plastic bags are durable and also reusable, so you can protect a lifetime of filament rolls with a very minimal up front investment.

*Count on using 2 silica gel packs per roll of filament – so the number of rolls you have to store will determine how many gel packs you need. They come in 20 to 200 pack bags.

NOTE: If you have more than 10-20 rolls of filament to store on a regular basis, you may want to consider investing in, or making, a humidity controlled cabinet.

What we'll be making is a simple, dehumidified environment for each roll to live in. One plastic bag and two silica packs per roll is all that's needed to give the filament a very healthy, long life!

Step 2: How to Save a Damaged Filament Roll

If you have any filament that has already absorbed too much moisture and is producing poor quality prints or jamming up your nozzle, DON'T DESPAIR! There is an easy fix for getting that filament back on 'dry land' and to being totally usable again.

How to Dry ABS and Other Filament

  • Preheat the oven to 140°F - 160°F (NOT CELSIUS)
  • Place the wet, damaged roll of filament in the oven for 5 hours

How to Dry PLA Filament

  • Preheat the oven to 120°F (NOT CELSIUS)
  • Place the wet, damaged roll of filament in the oven for 7 hours

For all types of filament, leave the oven door cracked open a bit and turn on the overhead fan.

This is like hitting the restart button on any damaged filament. Once it's dried out, continue with the following storage steps to prevent it from getting 'wet' again.

*To learn more about the science behind why and how filament gets wet – and to see photos of what prints made from healthy and damaged filament look like, check out this great article from the Matterhackers site.

Step 3: Date the Roll & Bag

The rule of 'lifespan' thumb for a roll of PLA or ABS filament is 12 months (check with the manufacturer for other types). This is why I like to mark my rolls with the calendar date it came in the mail. *You can also date its storage bag if you'd like.*

It's safe to assume that at least 1 month (maybe 2) has passed since the roll was manufactured – due to transport and storage times as it changed hands from manufacturer to fulfillment house to you, so I usually try to finish each roll within 10 months of those written dates.

Step 4: Reinforce the Bags

  • Cut two 3" pieces of duct tape.
  • Stick one (in half) to each top side of a one gallon plastic storage bag. (like pictured above)

This is important to do because the sides of the bags can easily split over time as you take the filament roll in and out. This reinforces those weak points and gives the bag a very long life.

Ta da!

Step 5: Load the Bags

  • Next, load a roll of filament into the bag.

  • Add two silica gel packs to the bag.

  • Seal the bag, making sure that it's properly closed the entire way.

TIP: Stop an inch short of sealing it and press out as much air as you can before sealing it all the way!

The only thing left to do is to stack your safely stored rolls in their designated home!

NOTE: If you're trying to make tall stacks, the bags can make this hard due to their 'slip and slide'iness. An easy fix for this is to place a 1/2 or 1/4 sheet of regular printer paper in between each bagged roll. Slip problem solved!

And that's it! Like I said, it's a VERY simple solution to a potentially expensive problem.

There are of course other ways of protecting your rolls that work well, like vacuum sealed bags and plastic bins with larger desiccant packs, but I find both of those solutions cumbersome, as the vacuum machine takes up more space and requires an extra step each time you use a roll, and the bin is larger and harder to hide away.

In my opinion, individual bags is where it's at! How do you feel about it? Please feel free to weigh in in the comments section below.

Happy making everyone!

Paige :D



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    33 Discussions

    What kind of oven lets you heat it up only to 50 ºC? And instead of putting "NOT CELSIUS", what about being useful and actually putting the Celsius values for us sane users of the superior metric system?

    Just to correct back to basics about polymers and moisture!

    The moisture content on it´s own doesn´t degrade the polymer. Most thermoplastic are hydrophobic and will find its own equilibrium in any environment. A dry winters day won´t present problems compared to a rainy summer.

    The problem you face is mostly due the humidity in the polymer creating vapour which is visible mostly on the surface of the melt but also creates voids inside the frozen solid.

    Only a very few thermoplastics degrade chemically from water content and to my knowledge ABS is not among those. Beware of PET.

    So what you are facing is water boiling inside the melt due to the rapid transformation from solid to melt. Drying the polymer prior to melting of course lowers this risk as the moisture level is reduced. I kindly advice all of you printers to go to suppliers of thermoplastics websites to gather a better understanding on this issue.

    Just look for drying process for type of polymer, it will vary with type and grade

    But drying is the way, always! And it will take time to achieve.

    Try to get a dough rise in 30 seconds!

    Good luck, keep on printing,

    Regards, Ernie

    1 reply

    Just to correct my own mistake as I couldnt find a way to correct inside my comment. Most Plastics are HYDROPHILIC. They absorb water!

    I would like to hear more about the expected "lifespan" of filaments. This is the first place ever that I hear about it and it kind of shocked me. What happens to the filaments when they exceed the expected best before date? Why isn't that marked on the spools and communicated by the manufactures if that's a serious issue? I at least have never noticed that information anywhere yet. I guess it might be in some manufactures datasheets then....not the ones I have used though.

    2 replies

    The plastic doesn't miraculously self destruct like on Mission Impossible but after a year unless it is vacuum selaed and protected by desicant or kept in a dehydrated chamber it will have absorbed enough moisture to destroy your hot end and make lousy prints.

    We have used filament that we have laying around for YEARS but as I said we run it thru a dehydrator to get the moisture out and then redate the container for another 12 months

    Only PLA degrades at any level of concern and ONLY if left in moisture so the corn molecules degrade so the key is no moisture

    We print hundreds of surgical models so we can do the surgery before the OR day and all the prints need to be fairly accurate and only last a few weeks or months but there is definitely a difference with moisture laiden filament and not

    Dr Dave

    Hello Dr. Dave, thanks for your feedback. I supposed that "shelf life" always refers to the product being stored within the parameters (temp., light, moisture etc...) given by the manufacturer. Any product can of course be destroyed in a short time by poor storage. That is basically what this instructable is about, the storage aspect. From the instructable though I got the impression that even with optimal storage there is this shelf life issue. And some people are probably mixing the two together in all different combinations and the discussion leads nowhere. So what really interests me is this shelf life issue when you have the condition of optimal storage given. After reading this I googled some other forums about this and the discussions basically follow this patterns: First person: Oh no my manufacturer said that my filaments have a shelf life. And it is really short too! Second Person: Store your filaments like this..... and you wont have any of those problems. Third Person: Plastics do degrade over time even in optimal storage and it depends on your material etc... ;-)

    So I actually just wondered where the 12 month statement in the instructable came from. Experience?


    9 months ago

    Would a dehydrator (eg for fruit, beef jerky etc) work for rejuvenating printer supplies that had been left out for a year?

    I haven't seen anyone mention silica gel with an indicator. That's what we used in our desiccators at DuPont. If it is dry it is blue. If it starts going pink, redry it. I didn't do an exhaustive search for the best price, but here is what I'm talking about

    Are the silica packs cheaper or more expensive than buying a big bag of crystal kitty litter?

    4 replies

    TOTALLY different material

    Silica although "relatively safe" is not to be ingested like kitty litter might

    You can get Silica in sacks on eBay for about $8 per sack of about 8oz or about 3" by 9" by about 2" thick basically a HUGE sack in comparison to the tiny little packs you get in cameras.

    Dr Dave

    The number one selling litter in the USA is Fresh Step here is their contents:

    Fresh Step® Regular Clay litter contains a high-quality non-scoopable clay, fragrance and borates. Fresh Step® Scoopable litter with the power of Febreze™ uses a proprietary technology containing premium scoopable clay (sodium bentonite), limestone, activated charcoal, fragrance and an antimicrobial agent (borates). Febreze is developed specifically for the product application, and it is designed to be used in litter and safe for your cat.
    They do sell a silica containing product but that one is FAR too "dusty" and the dust will get on the filament as it passes into the extruder and hot end and will mess up the lining of the PTFE tubing

    Since the whole idea is about LIMITED quantity and re-use buying bags of this to save money doesn't help the issue. The cheapest PURE Silica Gel is all you need since it will last a life time since all you do is pop it in an over for 60 miites and cool it back off and re-install it in the filament stoarge

    Dr D

    I explicitly did say "crystal", so the clay litter ingredients aren't relevant.

    I expect all silica gel is dusty (the Fisher Scientific MSDS does mention dust as an issue), which is why one doesn't use it loose. I keep the kitty littler tied up in old pantyhose, and I haven't seen dust, or had problems with the filament.

    I use it for filament, for odor/moisture control in climbing shoes, and for drying out electronics that had an unfortunate meeting with water. Handy stuff to have about. Some people use it with cats, but I don't have any cats.

    Note that says that you need at least three hours for drying a silica gel packet in the oven. At average US electricity cost, that is about 72 cents (counting about 2000 watts at 12 cents / kwh; it'll cost a bit less in winter when running the oven lowers heating costs and a bit more in summer when it raises the air conditioning costs).

    To break even over the $10/9lb cat litter's equivalent of 18 packets, you'd need to re-use your packet about 35 times, if my inexact calculations are right. That's a lot of re-use: I am not sure the packet can stand up to that.

    Hmm, what about using a big plastic container with a lid filled with those cat-litter silica balls (on the ground) - oh you wrote about them at the end.
    Also I must admit I was never really thinking about how to "store" my filament spools properly. I just had them in a drawer for about 2 years already without any extra caution. They all still print like on the first day.
    So I'm just wondering how sensitive PLA really is - I always thought it's just plastic and so robust like nothing else but now it appears like a fragile piece of a wedding cake ;-)

    Sometimes my printer goes for weeks without use so my storage is right on the printer,lol. I switched to only ABS to avoid the degradation issues of PLA.

    2 replies

    ABS is much worse then PLA

    The solution as we use is to build a small airtight box that is completely separated from the environment. The filament is inside the box then the box is connected to the extruder by a long section of PTFE tubing. The extruder is enclosed and then of course there is PTFE from the extruder to the hot end. So the entire route is completely isolated from the room air so no concerns abotu moisture at all. The box has a sack of silica we but it online in large sacks about 8ox each or so they are fabric sacks and go into the oven to drive the moisture when they need to be recharged

    Although our daily working printers go thru filament far faster then is a concern we have design and prototype units that are like you used infrequently so we need to be careful

    Dr D

    I don’t know why you would say ABS is worse. I’ve had absolutely no problem printing with ABS without any special storage. PLA on the other hand gets brittle and prone to breakage.

    Your totally isolated system sounds interesting for PLA, but I certainly don’t need it for ABS.

    Thanks for sharing this info. I didn't know 3D printing filament could absorb water. Does that mean that 3D printed objects are also prone to absorb moisture and weaken over time?

    1 reply

    No worries, humidity is only bad during extrusion.