My school didn't either, because it's a school. Schools are there for the basics, and home is where you perfect them IMO.
I'm going into game design, Armstrong does not have it and does not go into it deeply. I'm very sure the best I can get out of them is programming and thats not what I plan on doing. If thats all they teach about it, then what was the point in getting all this software!? If a school does not have it at all, HOW CAN I PERFECT IT!?
So I just have to ask, how exactly are you making those grays, then?
I get a round paint brush and dip it in water, dip the very tip in a tiny bit of ink, dip it in water again, apply on scratch sheet to get the value I want and then I apply more water if too dark, then I ink on the gray values.