This request isn’t about anything 3D printed, it’s about the terrain you have the prints on. For example, looking at the Doom Ramparts you have them sitting on a redish-black terrain piece. How do you make those and what paint do you use?
the reddish black terrain piece is just a cut section of polystyrene that has been painted red and black, and the spikes are the tormented scatter just painted red. they are often also sitting on a deep-cut studio battle mat (the lava mat)