Themes
Handwriting as the printer's model
Walker's history rests on one idea: 'as long as the latter was good the printers had a living model to go by, but when it decayed printing decayed also.' His slides pair manuscripts with early printed books, and the resemblance strikes Wilde as 'most curious and suggestive.' Aldus's type is said to come from Petrarch's hand, and the Vicentino copy-book leads to advice on improving modern copy-books.
Harmony of type and ornament
For illustration Walker's rule is that 'No ornament or illustration should be used in a book which cannot be printed in the same way as the type.' Mechanical and artistic harmony go together. A steel engraving in Rogers's Italy and a 'florid, pictorial and bad' American magazine page are his warnings, and Wilde hopes that publishers in the audience will heed his remarks on the pictorial excess of modern illustration.