Pick up a book that was sold at Paul Elder’s bookshop, and open to the inside back cover. Quite often, in the lower-left corner, you will find—for want of a better term—a “postage stamp”. The size of an actual postage stamp, and moistened in the same manner, they were affixed to many of the books sold in the shop. And not just Elder’s own publications, but all the other books too. This appears to have been a very common, but not universal practice.
The earliest known stamp (A) dates from 1899, before Elder and Shepard began to use the tomoye. It looks rather like a heraldic design: “per pale argent and sable on a vertical arrow, a seahorse traversed.” At this point Elder was still calling himself “D. P. Elder”.
The earliest known tomoye stamp (B) is from 1901, by which time Elder had dropped his given first name “David”. The Santa Barbara (C) and San Francisco (D) stores each had its own stamp; perhaps New York did as well but that has not been seen. Stamp E, featuring a tomoye surrounded by delicate tracery, had the longest lifespan, and is seen throughout the the 1910s and 1920s.
By the 1950s, much had changed. Paul Sr died in 1948, and Paul Jr moved the bookstore to the corner of Sutter & Stockton. The company still maintained the postage stamp tradition, but they had graduated to self-adhesive stickers (F) with a decidedly modern look to match the decidedly modern store.