Bryan Appleyard writing for The Economist’s 1843:

The more important innovation, however, was aesthetic. It is hard to describe exactly the look of a Tri-X picture. Words like “grainy” and “contrasty” capture something of the effect, but there is more, something to do with the obsidian blacks produced by the film and with a certain unique drama that made the rock photography of the Sixties and Seventies so powerful and distinctive.

Ilford was the black and white film of choice for many shooters. I, however, have always preferred Tri-X for its subtle, silky rendition of the images. ISO 400 film shot in ISO 800, and pull-processed back to ISO 400 was my secret development recipe then.