Homemade resin bases.
My girlfriend and I work in collaboration here - Katerina sculpts the initial models, then I make a mold and cast copies out of resin. Bases are cast from SmoothCast material under pressure. There are few examples of what we made. Bases, and also some tray kits, that can be assembled in any way needed. Mangler squig is from GW. All bases sculpted by Katerina and painted by me.
We make bases for commission. Basicaly, we can make almost any desing you want - just give us some references and we'll do the rest.