<p>The color changing material used in the filament is most likely a <a href="https://en.wikipedia.org/wiki/Leuco_dye" rel="nofollow noreferrer">Leuco dye</a>.  There are several types and some can be abrasive (just like the glow in the dark dyes); but, they aren't like putting sand through your nozzle.  Since brass is really soft, even something like the dyes can cause it to wear; but, it will take a while.</p>

<p>The safest bet is to use a hardened nozzle; but, if you are just doing a small print then it probably won't be too hard on the brass nozzle either.  I have heard of people printing an entire spool of glow-in-the-dark PLA with a brass nozzle then examining the nozzle and not noticing any wear.</p>

<p>Also, some people like the better thermal characteristics of the brass over the steel; so, they just stick with the brass nozzle for everything and replace it when needed.</p>

CC BY-SA 4.0
2019-04-30T19:48:53.020Z
2019-04-30T19:48:53.020Z
markshancock
<p>I've seen comments about glow-in-the-dark filament being abrasive and would damage a bronze nozzle so a hardened nozzle is recommended.</p>

<p>Is the same true for filament that changes colour when warm (for example when held in your hands)?</p>

CC BY-SA 4.0
2018-11-27T19:35:19.000Z
do you have a particular band in mind? there are different types of color changing, ranging from "rainbow on a spool" to "changing the color based on print temperature"
Trish
CC BY-SA 4.0
2018-11-27T19:37:12.370Z
Oops, I'll update the question. Specifically I mean the type that changes color when it's warm (eg. when held). If it may vary depending on the type, then what to look for when deciding would be helpful. Thanks!
Danny Tuppeny
CC BY-SA 4.0
2018-11-27T19:39:54.523Z
a thermo-dependant color? hmm, depends on the pigment/coloration...
Trish
CC BY-SA 4.0
2018-11-27T19:42:55.730Z
How can I tell/find out which would/wouldn't work?
Danny Tuppeny
CC BY-SA 4.0
2018-11-27T19:49:18.647Z
The manufacturer would be the proper call for definitive info.
Trish
CC BY-SA 4.0
2018-11-27T20:12:44.870Z
I checked a few sites, and so far didn't find any mention on any of them (neither saying it was required, nor that it wasn't).
Danny Tuppeny
CC BY-SA 4.0
2018-11-28T15:43:10.157Z
I know I'm in the minority, but my recommendation is always "try it and see what happens, because brass nozzles are dirt cheap and easy to replace"
Carl Witthoft
CC BY-SA 4.0
2018-11-28T18:44:45.197Z
How easily could I tell if it was happening?
Danny Tuppeny
<pla><nozzle><color>
Does color changing PLA require a hardened nozzle?
Danny Tuppeny
# Does color changing PLA require a hardened nozzle?

(Asked by: username_0 on 2018-11-27)

I've seen comments about glow-in-the-dark filament being abrasive and would damage a bronze nozzle so a hardened nozzle is recommended.

Is the same true for filament that changes colour when warm (for example when held in your hands)?

**Tags:** pla, nozzle, color
> **Comments:**
> **username_1**: do you have a particular band in mind? there are different types of color changing, ranging from "rainbow on a spool" to "changing the color based on print temperature"  
> **username_0**: Oops, I'll update the question. Specifically I mean the type that changes color when it's warm (eg. when held). If it may vary depending on the type, then what to look for when deciding would be helpful. Thanks!  
> **username_1**: a thermo-dependant color? hmm, depends on the pigment/coloration...  
> **username_0**: How can I tell/find out which would/wouldn't work?  
> **username_1**: The manufacturer would be the proper call for definitive info.  
> **username_0**: I checked a few sites, and so far didn't find any mention on any of them (neither saying it was required, nor that it wasn't).  
> **username_2**: I know I'm in the minority, but my recommendation is always "try it and see what happens, because brass nozzles are dirt cheap and easy to replace"  
> **username_0**: How easily could I tell if it was happening?  

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## 1 answers

### Answer by username_3 on 2019-04-30. Score: 4 | Accepted answer

The color changing material used in the filament is most likely a [Leuco dye](https://en.wikipedia.org/wiki/Leuco_dye). There are several types and some can be abrasive (just like the glow in the dark dyes); but, they aren't like putting sand through your nozzle. Since brass is really soft, even something like the dyes can cause it to wear; but, it will take a while.

The safest bet is to use a hardened nozzle; but, if you are just doing a small print then it probably won't be too hard on the brass nozzle either. I have heard of people printing an entire spool of glow-in-the-dark PLA with a brass nozzle then examining the nozzle and not noticing any wear.

Also, some people like the better thermal characteristics of the brass over the steel; so, they just stick with the brass nozzle for everything and replace it when needed.


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