<p>We currently have quite a few tags about filament:</p>

<ul>
<li><a href="https://3dprinting.stackexchange.com/questions/tagged/filament" class="post-tag" title="show questions tagged &#39;filament&#39;" rel="tag">filament</a></li>
<li><a href="https://3dprinting.stackexchange.com/questions/tagged/plastic-filament" class="post-tag" title="show questions tagged &#39;plastic-filament&#39;" rel="tag">plastic-filament</a></li>
<li><a href="https://3dprinting.stackexchange.com/questions/tagged/thermoplastic-filament" class="post-tag" title="show questions tagged &#39;thermoplastic-filament&#39;" rel="tag">thermoplastic-filament</a></li>
<li>etc.</li>
</ul>

<p>I feel like we need to clean these up and make clear what we'll use each tag for.</p>

<p>Thoughts?</p>

I see a form of hierarchy that could be used.
Depending on the question a higher level tag could be used or a more specific one for specific problems (or both tags even).
Filament
Plastic Filament
ABS
PLA
Water Soluble
PVA
Flexible
NinjaFlex and similar
TPU
Conductive
Metalic
Resin
Powder
Full Color
Feel free to edit to add more types