Epreuve de caracteres
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 page sells twice. The border is not decoration, it is inventory - every frame is assembled from the ornaments in the catalogue, so a buyer flipping for a text face is being shown the fleurons whether he asked or not. Setting the full alphabet, figures and ligatures directly under each specimen answers the buyer's real question, which is not how it looks but what actually comes in the box. The preface does the positioning work: an unknown Brussels foundry has no reputation, so Rosart borrows one by claiming authorship of the types that made a rival famous, and makes the claim falsifiable on purpose by telling the reader to go compare the specimens. Showing the script type as a real letter announcing a marriage, rather than as a pangram, lets the buyer see the face doing the job he would buy it for.
Steal this when
Steal this when you are a new name but your work is not - point at the output the market already admires, claim the part you actually made, and hand the buyer an easy way to verify it himself. Also steal the border trick when your packaging can be made out of your product.