As you can tell from reading this thread (wanna go back a dozen or so pages??) the idea of doing make-up is really very much part of Bill's baby... he generously gave me a few pointers on where to plug in what... to kinda give me a taste for what he's doing and where his shaders (and ultimately, to some degree, VSS) are going and because he knew I wanted to play. Thank you, Bill.

Let there be no mistake: Bill's the master of this craft, and I, but the sorriest of fumbling apprentices. (accurate depiction, Bill? I kinda think so!) He knows these nodes by heart and knows not only how they all play together but what would need to happen for any new parameters (like what I'm wanting to do: superimpose one texture over another) to work properly. I'll go ahead and develop masks - I can always do that - but structuring nodes is a little (okay, a LOT) beyond me, and it's not for lack of trying. I've put the obligatory hi-res ball up and played with adding nodes, trying different maths stuff and fooling around, but it certainly wasn't a very structured, scientific approach. It would be great for someone somewhere between Bill's awesome brain-force and us Neanderthals to kinda provide an introduction to this in a way that makes nodes and what they do meaningful to us in a Poser-focused manner. Yes, I know specular. Know what diffuse does. Can set up transparency. It's when you decide you're not going with the PoserSurface diffuse connection - you're going to use Alternate_Diffuse (and why) and then... well, realizing from which direction nodes should be analysed. We End UP at the PoserSurface MegaNode, but where did we start?

The ImageMap?
I guess.

When I first had a look at the Material Room, I didn't get that concept of 'feeding' at first: a node feeds another some colour or texture information, which get processed along with whatever else that node deals with... and then THAT information then gets fed to another node.

This is why my eye-liner is still fading into my eyeshadow. Yes, I could kludge this and make sure my masks didn't overlap, but I know there is a way for one shader set to have eminence over another... gotta be.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks