Before I could figure out what to do with this, I needed to know what the words mean. Because there is “material” and “materiel.” I’m good with words, but I never remember which is which. So if you are confused:
Unless you are using tanks in your pictures, I think definitely material.
Almost everything in our world is made up of more than a one material. Furniture, appliances … virtually everything we use is compounded. Natural things are complex too. A tree it isn’t wood. It’s sap, leaves, roots and more. The air is full of dust and other natural (and not so natural) particles.
I’m looking for a thing made up of only two things. To make this work, I will have to count compounded material as “one” thing, and “other” stuff as “another thing.”