I have an UV-mapped a mesh with a diffuse texture perfectly mapped, that appears in materials view.
Now, for ONLY specific parts of a texture, I want to overlay (as in screen, darken, multiply, soft light, overlay) another texture on top of a specific area of the diffuse texture. How is that typically done in blender? I don't want normal maps, I don't want specular, I just want diffuse and then alpha with overlay, likely using the mixRGB node.