The 1929 American Annual of Photography article, "The 'Fresson' Direct Carbon Printing Process" by Charles M. Mouret, was mentioned.
I happened to have that particular AAP, and, more surprising, found it, and absolutely no surprise, it was bookmarked at that article, which of course I re-read -- confirming, as mentioned, that it told (in detail) how to develop a print on the proprietary Fresson paper.
But, little as I desire to go that route, it leaves me more puzzled than ever: Why is it that the so-to-speak best minds of the field (give or take a few other minds), WITH the aid of the Internet AND modern photo knowledge have not been able to, or claim not to have been able to, duplicate that paper -- invented at a time, incidentally, when potassium dichromate crystals were still called "powder" (vide Mouret). How much could they have known that "we" don't know?
Art Chakalis wrote a (charming, if I may say so) article about his visit to the presentday Fresson studio for Post-Factory; he himself has patented a process of direct carbon, which I admittedly have not tried, but which obviously works, yet Art claims not to have found the "secret" of the original.
John Grocott has likewise developed a process, apparently not (yet anyway) patented, but still it also "works." I'm forgetting the name of the fellow who wrote about his discoveries in Silverprint, some 10 or more years ago. Others, perhaps MANY others, have worked on the problem, yet it seems, whatever their other successes, the "original" "Fresson," the holy grail (?), eludes them.
Sandy King, world-class expert on carbon printing, with publications & triumphs worldwide, plus advising (I gather) Bostick & Sullivan on their recent commercial carbon paper, yet -- IIRC, Sandy has rarely so much as uttered the word "Fresson."
Perhaps he, and others, achieve what Fresson can't, but the world still seems to long for a paper to buy and print on.
Maybe I don't have enough problems. (I took a holiday today, walking to Chelsea to enjoy & disenjoy some current art) but still I ask: How did those folks, without a computer or a sensitometer or a 21-step, let alone an MFA, devise a process posterity cannot match? Or is that simply nostalgia, a longing for temps perdues (the feeling, not the chickens), & the main difference is lack of the commercial distribution of Mouret's time?
PS. My own favorite feature of the American Annuals (the commentary, as a rule, being vapid and long-winded) is the list at the back of the book, "Who's Who in Pictorial Photography" world-wide: some 19 pages from America to Tasmania, circa 1500 photographers: The two most exhibited in salons of 1927-8, BTW, were Dr. Max Thorek of the US (211 prints), and Frantisek Drtikol of Czechoslovakia (142 prints). Wm Mortensen, incidentally, was slacking off, with only 18.