Buried near the end of the table of contents for Volume V of Schriever's massive photography course is a chapter title that stops the modern eye cold:

CHAPTER XV. Part XII — Carbons on Watch and Cigarette Cases, Watch Dia[ls]...

An entire chapter — sandwiched between eleven other chapters on the "Carbon Process" — devoted to transferring photographs onto the metal of pocket watch cases, cigarette cases, and even watch dials themselves. This was 1909. Long before UV printers, dye sublimation mugs, or Shutterfly's photo-on-anything empire, an ordinary photographer's manual was teaching hobbyists how to put a face on a piece of jewelry.

The Complete Self-Instructing Library of Practical Photography was a ten-volume correspondence course published by the American School of Art and Photography in Scranton, Pennsylvania. Edited by J.B. Schriever, it was pitched at working photographers and ambitious amateurs — the sort of person who might apprentice by mail. Volume V alone covers albumen paper, plain salted paper, and no fewer than twelve parts on the carbon printing process, which by then was already considered old-fashioned but was prized for its permanence and its ability to be transferred onto surfaces other than paper.

The carbon process worked by exposing a "tissue" — a gelatin layer loaded with pigment (usually finely-ground carbon black) and sensitized with potassium dichromate — to sunlight through a negative. Wherever light struck, the gelatin hardened. The unhardened parts washed away in warm water, leaving a pigmented relief image. Because the image lived in the gelatin itself, that gelatin could be squeegeed onto almost anything before development: opal glass, porcelain, ivory, leather — or the polished lid of a silver cigarette case.

This is genuinely forgotten knowledge. The chapter titles that surround it — "Care of Material and Detailed Instruction for Sensitizing the Tissue," "The Double Transfer Process," "Double Transfer from Plate, Opal or Ground-Glass" — describe a craft ecosystem that has almost entirely vanished. Carbon printing survives today only among a few dozen fine-art practitioners worldwide, most of whom order pre-made tissues from a single Czech supplier. The idea that a Scranton bookkeeper could once send off for a lesson booklet and learn to put his wife's portrait on his own cigarette case is astonishing.

What modern readers might miss is the sentiment behind it. The Edwardians were obsessed with portable, personal memento mori — lockets with woven hair, mourning brooches, miniature portraits. Photography on watch cases wasn't a gimmick; it was the direct descendant of miniature-portrait painting, made democratic by chemistry. When you flip open a smartphone lock screen today to show a friend a picture of your kid, you're doing exactly what a 1909 gentleman did when he clicked open his pocket watch.

The medium changed. The impulse didn't.