Looking at old postcards and photos of studio portraits from 1900-1910 I am really fascinated by the incredibly soft tones and gradations that they have, so I am curious what processes were the most common at the time when it came to shooting and printing.

I know that by that time multiple options were already available in terms of plate and film stocks, but history books tend to be really vague about details, so I was wondering if anyone has more info on this.

I have been trying to track down some photo journals from the time (the British Journal Photographic Almanac would likely have details on "the latest trends") but so far I have not had any luck with this.