well, half of me says to take it up seriously, if we are ever going to get to decent useable shared materials libary thing, which is holding us back. Look at 3DSmax, etc heck even DAZ comes with a pre-loaded and pre-defined material set, and not just medium-gray on the Add New. The Library script, if it is fixed by now, would make a great interface to a subdirectory where these are stored. But organizing it would be a be-ach.
The other half says why bother let everyone figure it out on their own time to take a nap you old fart who needs help anyway let someone else do it and what is so wrong with re-inventing the wheel over and over and over and over and over and over and over and over and over again anyway it’s good experience maybe i should use some punctuation.
In answer to your question, an infinite number; practically speaking you could get three nodes, like glass.frosted.gr where gr is an ISO standard color abbreviation. English, of course
A possible starting set of Top level Nodes seem to be, in light of old, sss, and now caustics:
Flat, Gloss, Satin (no SSS etc-old skool)
Plastic. Glass, Skin, Metal, Wood, Stone, Paper, Emulsion, … (new skool)
So, for example, <and these would all need to be defined,> Skin is the covering of an organic thing, like a fruit or a human or a cat. So you have skin.grape.rd, or skin.human.tn, skin.apple.yl (for the golden delicious apple, not the green tart skin.apple.gr or red delicious skin.apple.rd), and of course a very special and hotly debated skin.suzzanne.??.
I’m not suggesting we define the world here, or be the most authoritative source, but trying to guide people in creating these materials, and them getting good results with nothing to start with, is sorta unreasonable. Also, asking every good post to post their settings, well, there’s about a hundred settings that now go into a material, so it would be easier to say it is X plus these tweaks, rather than Click Add New. RGB is…Shader is toon…spec is Oren, settings are .3,.4,.5, respectively. Disable ior, but an emit of .02, and …