I am looking to create scratches, swipes, brushes, similar to the reference image provided, that will only appear where I wish them to (as shown below).
What is the best Node Group/Layout/Structure/Workflow to implement such scratches/brushes (purely) on top of a material?
For clarity, I have provided the reference image below, as well as the blend file, with the texture in the node setup. http://pasteall.org/blend/index.php?id=47820
I also dispose of materials from Poliigon, if that is of assistance.