<p>Mick's suggestion is a good one. PLA may shed some color in acetone, but ABS will dissolve completely in a suitable amount of time. If you have dark filament, you can test by flexing the filament until it breaks. ABS will sometimes/often/usually fatigue with a white break line, while PLA does not exhibit this tendency as much.</p>
<p>PLA has a somewhat sweet smell, which may be the corn sugars burning off, while ABS has a much more chemical-like odor.</p>
<p>Not doing heat testing does limit your options.</p>

CC BY-SA 4.0
2020-09-24T11:59:36.610Z
PLA dissolves in chloroform. It's hard to get, but it's part of 3D gloop for PLA: https://www.3dgloop.com/
amra
CC BY-SA 4.0
2020-09-24T00:34:39.400Z
2020-09-24T00:34:39.400Z
fred_dot_u
<p>Just burn it and check flame color.</p>
<p>I know you mentioned that you would like to avoid heat test, but this method is much faster and easier then other techniques.</p>
<ul>
<li><a href="https://www.youtube.com/watch?v=bNKno20GMMQ" rel="nofollow noreferrer">3D printing filament burn test</a></li>
<li><a href="https://www.youtube.com/watch?v=a7l0Aaysy_8" rel="nofollow noreferrer">Do 3D Prints Catch Fire? ABS / PLA / PETG Burn Test - Episode 1</a></li>
</ul>

CC BY-SA 4.0
2020-09-24T12:03:09.467Z
2020-09-24T12:03:09.467Z
amra
<p>So I have some old filament that I originally got for a 3D pen. The problem is it's unlabeled and I haven't been able to find anything that might help me distinguish whether it's PLA or ABS. The bag it all came in says that wherever this filament came from only makes PLA and ABS so it's got to be on of those two.</p>
<p>I have a roll of PLA in my 3D printer right now, but I can't tell if it's the same as the filament I have for the 3D pen. It's been a while since I've used the 3D pen, but I do remember whenever you used it, it would produce a very very bad smell. I've also noticed that the filament seems to be more flexible that the PLA in my machine. This makes me think it could be ABS, because the PLA smells far better than what I remember the 3D pen smelling like, and it's more flexible.</p>
<p>I also don't really want to do any heat tests or anything on the filament, so if the smell and flexibility is enough to determine which filament it is, could anyone tell me?</p>

CC BY-SA 4.0
2020-09-24T00:22:51.227Z
Does it dissolve in acetone? If so, it is ABS.
Mick
CC BY-SA 4.0
2020-09-24T20:16:55.187Z
some good advice in this previous post

https://3dprinting.stackexchange.com/questions/3728/identifying-the-plastic-type-of-an-unknown-spool-of-filament-or-recyclable-waste
Diesel
<filament>
How to identify what type of filament an unlabeled spool is
Mike
# How to identify what type of filament an unlabeled spool is

(Asked by: username_0 on 2020-09-24)

So I have some old filament that I originally got for a 3D pen. The problem is it's unlabeled and I haven't been able to find anything that might help me distinguish whether it's PLA or ABS. The bag it all came in says that wherever this filament came from only makes PLA and ABS so it's got to be on of those two.

I have a roll of PLA in my 3D printer right now, but I can't tell if it's the same as the filament I have for the 3D pen. It's been a while since I've used the 3D pen, but I do remember whenever you used it, it would produce a very very bad smell. I've also noticed that the filament seems to be more flexible that the PLA in my machine. This makes me think it could be ABS, because the PLA smells far better than what I remember the 3D pen smelling like, and it's more flexible.

I also don't really want to do any heat tests or anything on the filament, so if the smell and flexibility is enough to determine which filament it is, could anyone tell me?

**Tags:** filament
> **Comments:**
> **username_1**: Does it dissolve in acetone? If so, it is ABS.  
> **username_2**: some good advice in this previous post  https://3dprinting.stackexchange.com/questions/3728/identifying-the-plastic-type-of-an-unknown-spool-of-filament-or-recyclable-waste  

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## 2 answers

### Answer by username_3 on 2020-09-24. Score: 6

Mick's suggestion is a good one. PLA may shed some color in acetone, but ABS will dissolve completely in a suitable amount of time. If you have dark filament, you can test by flexing the filament until it breaks. ABS will sometimes/often/usually fatigue with a white break line, while PLA does not exhibit this tendency as much.

PLA has a somewhat sweet smell, which may be the corn sugars burning off, while ABS has a much more chemical-like odor.

Not doing heat testing does limit your options.

> **Comments:**
> **username_4**: PLA dissolves in chloroform. It's hard to get, but it's part of 3D gloop for PLA: https://www.3dgloop.com/  

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### Answer by username_4 on 2020-09-24. Score: 1

Just burn it and check flame color.

I know you mentioned that you would like to avoid heat test, but this method is much faster and easier then other techniques.

* [3D printing filament burn test](https://www.youtube.com/watch?v=bNKno20GMMQ)
* [Do 3D Prints Catch Fire? ABS / PLA / PETG Burn Test - Episode 1](https://www.youtube.com/watch?v=a7l0Aaysy_8)


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