how do i overlay a simple Noise texture onto my painted diffuse patterns to put some random grime on it? i’m trying to run the noise through a Multiply mix so the white vanishes and the black should darken my design, but it’s not working.
TIA
Run the noise texture through a colour ramp node set to constant - then move your black/white parts of the ramp to set the noise to the desired level.
thanks moony, i’ll give it a try tonight.
still can’t get that to work. tried running the output into a MixRGB, and then tried adding in a transparency so the white was transparent and the black should have been left to multiply/darken the image, but it’s not working.
magic, thanks very much moony 
hmm, actually i don’t think that’s what i want. i want the diffuse image to cover everything but the blotched noise to be overlaid to darken it like grime.
Plug the noise and color ramp into the displacement socket instead of the mix fac.
Add a math multiple after the color ramp to adjust it on the strength. You’ll also need a texture coordinate node into the noise to get more control.
? i don’t want it displaced, i just want it to darken.
That’s fantastic Photox, thanks very much for that