That cut-away shows a section of the tank that has SLA and SOFI. The dark stuff to the left is SLA (Super Light Ablator). It is an ablator that is basically tiny chopped up cork particles mixed in with a silicone binder matrix. In areas of the tank where it is needed, it is under the SOFI, up against the outer tank wall. On top of that is the SOFI (Spray On Foam Insulation) and that can be one of several different formulations.

Again, just to be certain we are still on-topic: some of these materials were flown to their place of application by turbine powered planes.