The white material is what we call "3/4 down" (limestone rocks and dust) for the base - not sure that the term is the same everywhere or not.
My patio area is about 500 sq feet in a kind of kidney shape and I have about 7-8 inches (13 yards) pre-compact level. That picture is before I had all the material in place, I have since had more material added to bring it to the level desired.
Thanks for noticing though. Helpful folks here.
