Epreuves des caracteres de la fonderie
The pattern
This still is filed under Specimen as proof.
Define
A specimen (type, material, finish) is shown so the product proves itself under comparison.
Mechanism
Controlled display. Same conditions, side by side, no adjective required. The sample is the sentence.
Verdict
Buyers choose by eye or by hand and we can put the real thing in front of them.
Why it works
The medium is the product, so the piece never argues - it exhibits. The mechanism that makes it readable rather than a sample chart is continuous copy: one long narrative on the history of writing and printing runs across the whole size ladder, so the eye reads a story while it is really comparing typefaces on identical subject matter. That holds the buyer through two hundred pages of what is technically a parts list. Numbering every character and ornament converts a browsing object into an order form and removes the friction of describing what you want. The preface pre-empts the obvious objection - that the book shows the limit of the stock - by stating that any character can be cast on several bodies, letter-spaced or closed up, so the shown range understates the real range.
Steal this when
Steal this when your product can only be judged in use and a description of it is worthless - set the sample as the finished thing, at real size, doing real work. Hold one piece of copy constant across every variant so the buyer is comparing the product and not the content, and number the variants so choosing and ordering become the same action.