There is a kind of film that does not ask for your attention so much as keep it. The good training reel is one of them — a sequence built for the second and third viewing as much as the first.

We began this folio because that quieter craft had stopped being written about. The festival circuit had moved on, and what remained was a stack of unsigned films doing patient work in hospitals, classrooms, and union halls. They deserved a column. So we kept one.