Ceramic Composite is produced by surface refineries. It has high variance in production and consumption rates, so it can be vulnerable to weak links (or other planetary influence) overcoming it. The guaranteed build is to have a rocky world with no geo signals, and put two colony T1 planetary outposts on it (one of them shields the other from weak links elsewhere in the system, giving you a single-type refinery there which guarantees Ceramic production)
Insulating Membrane is produced by orbital refineries. It has consumption rates which can be 20x or more higher than production rates, so even a single weak link of a consuming type (industrial, high-tech or military) can stop exports. The guaranteed build is therefore similar to the above: rocky world with no geo signals, put two orbital colony ports of the same tier in orbit, one of them blocks the weak links from affecting the other. This gets very expensive if you want anything bigger than an orbital outpost, since you need to build a "decoy" Coriolis or even a "decoy" Orbis. Fortunately Insulating Membrane isn't required in high quantities so a medium-pad outpost might be sufficient.
Alternatively and especially in smaller systems you can carefully design the system so that nothing generates weak links, and therefore get away with only a single surface/orbital port at this rocky world. But that does significantly limit what else you can build in the system and it's quite possible that you've already passed that point in this one.