I read some pages about 3D filament burn test.

I have a white filament and made the burn test and not only it caught fire immediately and crackled (noise), but also I burned just 1 cm of it and it speckled black spots on the entire surface and furniture in my kitchen, just by burning a centimeter.

I've no idea of what type of filament this is.

It's white, not very elastic, it doesn't get too mechanically damaged when I fold it. On the other hand, it is a little translucent (just a little) but becomes opaque with the slightest fold.

enter image description here

In the picture, the dark parts are in reality white opaque parts, the the back light show then dark. The clear parts are part and slightly transparents.

When I bend this filament, it doesn't look anything like PLA or ABS, it's much more flexible and remembers the folds better.

enter image description here

This filament is not soluble at all.

What kind of filament could this be?

  • $\begingroup$ Hi Vincent and welcome to Stack Exchange! I have cleaned up your question and proposed a new title to better reflect the content of the body while maintaining the core of the original title. With a better title you are far more likely to get your question answered sooner. Please look at the edit and feel free to adjust by edit or add additional information (e.g. link to filament burn test articles). Please take our tour and read our help center. Thanks! $\endgroup$
    – 0scar
    Dec 1, 2023 at 7:30
  • $\begingroup$ Welcome. Good question. It's good for context to know where and when you got this piece of filament. And perhaps easier to track where it came from and ask. $\endgroup$
    – Bob Ortiz
    Dec 1, 2023 at 12:32
  • 1
    $\begingroup$ Thanks for your help in renaming the subject. I now have to find any trace about when we got this big spool (1.5kg). $\endgroup$ Dec 1, 2023 at 16:15
  • $\begingroup$ What is the 3d printer filament burn test? I never heard of this and have no idea what it’s for. You burned it for a few seconds with a lighter and black spots appeared all over the furniture in your kitchen? Do you mean a few black spots appeared near where the burning filament dripped, or every single piece of furniture in your kitchen is now polkadot? P.S Have you considered putting a piece of filament in an old toaster oven to see what temp it melts at? $\endgroup$
    – K Mmmm
    Dec 1, 2023 at 19:49

2 Answers 2


It's impossible to judge based on the photos alone; the properties you describe and the photos, to me, look similar to the polyhydroxyalkanoates (PHA) I've recently been testing. But my reference is only PLA and DHA, and it's a relatively new type of filament so, that is unlikely. Knowing when and where you got it, is perhaps relevant for context. Perhaps adding information about the smell when extruded, or colors of smoke or flame when burned, the observed melting point could help narrow it down too.

Generally for plastic identification. Preciousplastic.com Academy has good and free content about distinguishing different types of plastic such as in this YouTube video but I've never seen such floating tests for buoyancy be performed for filament specifically. The Brothers Make YouTube channel also has good content about plastic identification.

If you want a total overkill solution to test this tiny piece of plastic you could perhaps consider something like PlasTell by Matoha.com, which I believe used spectroscopy, as shown below. However, I have not seen this being applied on 3D printer filaments (PLA, PETG, ABS, TPU, PHA) as well.

plastic identification using spectroscopy

Source: Oceaninsight.com


10 years ago, we bought a spool of White HIPS, and one of White Rubber, and one of Wood and one of Nylon. I never used them ! Funny...

Surely I burned the HIPS one (I don't think it's a rubber one).

Now we know that burning 1 cm of HIPS can stain several square meters with small greasy black spots. In the air nothing is visible but after just 1 cm, it's a misery to clean... So do not do the burn test with HIPS !

  • 1
    $\begingroup$ You could have [edited] your previous answer and flagged for un-deletion, rather than posting a new answer. However, this doesn't really seem to answer the question, i.e. your question, unless the answer is the HIPS that you bought and then forgot about. Also, please take the tour to better understand how Stack Exchange works. Note that it isn't a forum of threaded messages, with "Hi" and "Thanks", this is a Q&A site. If you wish to thank someone, then please just upvote (and accept) their answer - there is no need to leave an anecdotal answer as a reply. Thanks. $\endgroup$
    – Greenonline
    Dec 2, 2023 at 14:26

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