I did this so long ago, I don't completely remember the specifics.

I took some Kodachrome 64 and High Speed Ektachrome slides and printed them on Agfa Brovira #6 paper (which is no longer available). This produced a high contrast black and white negative print. I then copied that on Kodachrome 64 to obtain a high contrast black and white negative. I then printed that on Agfa Brovira #6. The results were almost line drawings with virtually no grey tones. I even tried "solarizing" some of the photos by flashing a light on the paper as it came up in some old, nearly exhausted Dektol. I got some neat results doing that but it was a long and a pretty expensive process. These days, the same results can be obtained more easily with (dare I mutter such obscenities?) Photoshop or Paint Shop Pro. Still, it was a lot of fun at the time.