Can we have a "paint on glass" tag?
There are quite a few animation clips on the site that use paint-on-glass technique, but there's no tag for it. Can we have this tag? For example, most of the clips by miyo sato uses this technique. https://www.sakugabooru.com/post?tags=miyo_sato

There are some other japanese animations as well that use this technique but not on this site. such as https://myanimelist.net/anime/30862/Yubi_wo_Nusunda_Onna
It's been pitched a few times, but since we don't tag any other type of specific toolset, it didn't seem quite right. Since there aren't that many artists who do use it, making a pool for them should be pretty easy at least.
All right then. It seems someone has made a pool for this now and added the clips there. But could you explain a bit more about this "toolset" thing? "Paint on glass" does use glass as a tool, but shouldn't it be treated as an animation technique too? It makes sense to not have tools/devices like zoetrope or softwares like FLASH as tags, but "paint on glass" (or things like sand animation, erasure animation) seems like a different case and there should be a distinction. What other examples of toolset do we have on the site that doesn't have such tags?

Also, this kind of goes beyond the specific context here, but I have always wondered why "kagenashi" is a pool instead of a tag, could you explain me a bit of that too. Thanks.
The actual equivalent to paint on glass wouldn't be flash/whatever other software but "digital animation", which would imply an impossible tagging dichotomy with traditional paper animation. So for example, we've got a stop-motion tag since that's a bit on the fence but does refer to the animation's qualities, but not something like clay animation, which is a more specific "what did you use" type of deal.

As for kagenashi, it's a different case, because frankly it would fit the site's philosophy pretty well. I think the only reason that it hasn't been established as an actual tag is that it's often more of an approach than an absolute, so we're sparing ourselves the arguments that would spawn (already do elsewhere sometimes!) about what qualifies.