The end grain problem I'm trying to figure out how to create a render that accurately represents the effect of applying a clear coat or oil treatment to a wooden artifact such as a box with finger joinery or dovetail joinery such that the end grain of the objects are darkened.  What I've found so far simply applies the wood texture and there's no means of tweeking the faces that need darkening. Is this an easy fix or am I delusional?
You can go into the Node View and use different nodes like Coloramp etc to change characteristics of your texture. These can be bound to keyframes in your animation.