Back in 1989, when I went on my first Blakemore workshop John was printing on Agfa Record Rapid, as were Peter Goldfield, Peter Cattrell & Fay Godwin. The only other high quality fibre based paper at the time was Ilford Galerie.
Galerie being essentially a Bromide paper didn't have the flexibility of Record Rapid which was Bromochloride. Peter Goldfields trick was to cut a sheet of paper into strips and expose each for a different time, then cut each strip into squares. Then in the developing tray he would pull squares of roughly equal visible density out after maybe 15, 30 45, 60, 75, 90 etc seconds. After fixing and a quick wash he'd lay the square out with the roughly matching densities. You were struck by the quite different tonal colours.
So by varying the development time you could control the warmth of the paper, also the contrast, something you can't do with a Bromide paper.
John's approach to negatives was the same as Ansel Adams and Minor White, a negative that is a score that can be interpreted in different ways, which makes a lot of sense.
I'm not sure the exact year Agfa dropped Record Rapid replacing if with Multicontrast Classic, possibly 1993, I know I had to use MCC to make the final prints for a 1994 exhibition. It was equally as good, and flexible, as Record Rapid (last version with no Cadmium). The early Ilford Multigrade Fibre based paper was not in the same league. When Agfa pulled out completely I switched to Forte Polywarmtone which I think is the best paper I've ever used. I have a few sheets left.
Ian