5 ideas
Tschichold reconstructed a proportional canon from late-Gothic manuscripts and incunabula. On a 2:3 page, the text block has the same proportions as the page, and its height equals the page width. The margins run in the ratio 2:3:4:6 (inner, top, outer, bottom), which places the text high and toward the spine, so each two-page spread reads as a single unit.
Hired to fix Penguin's inconsistent mass-market paperbacks, Tschichold wrote the four-page Penguin Composition Rules. They covered spacing, indentation, punctuation, capitals and small capitals, and the handling of preliminary pages. He also personally marked up hundreds of titles and redesigned the series covers on a standardized grid, showing that cheap books printed at scale could meet classical standards through enforced house rules rather than extra expense.
In 1928 Tschichold published a manifesto demanding asymmetric, sans-serif, anti-ornamental typography as the only modern form. After being arrested by the Nazis and exiling himself to Switzerland, he came to see that absolutism as akin to the authoritarian mindset he had fled. He returned to centered, serif, tradition-based book design, arguing that a doctrine which forbids alternatives serves ideology rather than readers.
Book typography should be judged by how easily and pleasantly the text can be read, not by how original the design looks. When a design draws attention to itself, the reader is distracted from the author. The typographer's highest success is therefore a book whose arrangement goes unnoticed, because the reader's eye is served by conventions it already trusts.
Tschichold insists that a paragraph start with an em-quad indent and no extra space between paragraphs. Flush-left openings hide paragraph breaks whenever the preceding line ends near full measure. Added space between paragraphs breaks the even texture of the page. The indent is the one device that marks a new thought while keeping the text block a continuous, calm gray.