What to Do with the Last Bit of Filament? (Leveraging Excess Filament)

3D printing can be very rewarding whether pursued as a passion project or as a business. But if you have been printing for any length of time then you will know it can also produce a huge amount of waste.

While 3D printing produces up to 90 percent less waste than other manufacturing processes like injection molding, it still produces over 275 tons of plastic waste per year.

All prints produce a little bit of waste. But is there a way to recycle or reuse the waste so there is less or even none? That is what we want to explore today. We want to look at ways you can sustainably dispose of filament. If you’re concerned about reducing the environmental impact of filament waste, then keep reading to find out what you can do about it.

What Do You Do With Excess Filament?

The excess filament should be stored for later use. Very often, the filament from a print can be used for a smaller complete print or as part of a larger print. There are several ways you can use excess filament such as for making swatch cards, infills, or welding rods.

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All these we explore in the sections below so keep reading to get some ideas on what you can do with your remaining filament after you’ve finished a model.

Also, check out our post on ” How Much Filament Do You Have Left? Tips & Tricks Listed!

What Do I Do With The Last Little Bit Of Filament?

The last bits of filament can be used for performing useful functions such as calibrating a 3D printer, testing printer settings or it can be spliced with new filament.

Calibrating a printer

Printer settings can get thrown off after or during a print. Rather than use and possibly waste a new spool of filament while recalibrating a printer, the smarter thing to do is use the last bits of filament.

Testing printer settings

The last bits of filament are especially useful if you’re still new to 3D printing. You can use them to experiment with printer settings so you can get a better grasp of how a printer works without wasting filament.


A somewhat more complicated solution is to join the last bit to a new spool of filament. Splicing is a little complicated because melting and then joining ends together doesn’t always produce a filament roll that can survive being drawn into an extruder.

One very simple way to do this is with a lighter. You cut both ends, heat them then press them together until they cool into one roll. Source

For more on this we highly recommend that you check out our post ” Can You Splice 3D Printer Filament? How To Join 3D Filaments!

What Can I Print With Last Filament?

The remaining filament in a spool can be used to print infills, connectors, or as welding material for 3D models.

Infills for new prints

If you’re working on models that don’t require perfect infills then you can use the last bits of filament to make them. This would be the case for interiors that won’t be visible.

Making connectors

Some 3D models require connectors like rivets, pins, or hinges. This is where unused filament can come in handy.

Welding rods

You can also use your last filament as welding rods for larger prints if you have a 3D printing pen.

What Do You Do With The Filament After Printing?

The filament should be stored after printing. This ensures the filament does not go bad. Moisture, UV radiation, and dust can spoil filament and render it unusable which is why it needs to be stored so it is not exposed to any of those elements.

Filament can be stored in vacuum-sealed bags, food containers, dry boxes, or anything else that will prevent moisture buildup or exposure to light. As an extra precaution, drying agents like silica gel absorb the moisture in the container you choose to store your filament.

Properly storing filament is possibly the most important thing you can do to reduce filament waste. Filament goes bad if it is not stored properly or used before it expires. Filament has a shelf life of between 1 to 3 years depending on what type it is, so make sure you’re printing new projects! Source

For more on this, check out our post Does PLA Have A Shelf Life? How long & How To Store It for A longer Shelf Life!

How Do You Use The End Of A Filament Roll?

The end of a filament roll can be used on a new print or to make swatch cards. If there is enough roll it can be used for very small prints.

Using it on new prints

This is possibly the simplest fix. Just simply use the filament as part of your next print. Once it’s done, you can get a new spool and load it up in your printer and carry on with your print.

Check out our post Can You Respool 3D Filament? Why You May Have To & How!

Swatch cards

Swatches are useful for color coding your filament spools and keeping your prints tidy. You can use them to organize your spools by color, brand, manufacturer, or any custom dimension you need.

Small prints

If you have enough filament, there’s also the option of making miniatures of your larger models and prints.

Also, we recommend that you check out our post How Much Filament Is on A Roll? How Much Is Left on The Spool!

What Can I Do With Scrap PLA Filament?

Scrap PLA filament can be recycled. One important feature of PLA is that it is partially biodegradable. As it is made from organic material like cornstarch, it breaks down much more easily than filaments like ABS which are made from synthetic material.

Using PLA for compost

As it is made from natural materials, this technically means PLA is compostable. However, unless done with specialized equipment, it takes more than 10 years for it to break down, so recycling is a much more environmentally friendly option. Source

Recycling PLA through filament extrusion

Filament extrusion is where the PLA is ground up into small bits before being heated and melted to make a new filament spool. This process requires the use of a shredder and extruder so it may be a little more time and resource intensive.

We also highly recommend that you check out our post What To Do With 3D Printer Waste / Scraps? Must Know Tips!

How Do You Dispose Of Old Filaments?

The best way to dispose of old filament is to either recycle, reuse or repurpose it. This ensures there is a minimal amount of waste plastic produced and it is also a cost-effective way of spending less on new filament.

Other than recycling the filament yourself, there is also the option of using a recycling center if there is one near you.


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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