My fist study on ink/paint simulation using Substance Designer. That software is so versatile it always surprise me. :) BTW, I did not focus much on the height maps yet.
Far from perfect. But already happy with some results. I used some random images as sample for the inputs.
You can download that version of this project on my Marketplace here -> https://www.artstation.com/kumodot/store/DezD/paintfx-v01-procedural-paint-look-simulation