Perhaps I ought to go on that safe rule also; but as a foolish artist, with a rigid sense of propriety, I must sink my own interest and regard the book only as something outside myself.
My opinion is, that if a book is to be illustrated with more than a frontispiece and vignette, it ought to be illustrated thoroughly throughout. It ought to be an édition de luxe, or else a book with only a frontispiece and vignette.
I think that every book bound in cloth ought to have a frontispiece at least; if possible, also a vignette for the title-page. When I publish a book I always try to persuade my publishers to go to this expense.
If it is a novel of a sensational or exciting nature it does not require any more. The tasteful reader, when he takes up a book, likes to be introduced to it with a well-drawn, finely-executed frontispiece; he naturally looks at that first because it opens first to him.
He lingers for a space over that frontispiece, and is either attracted or repelled by it. If it is a bald, commonplace group of figures, without action or sentiment, something that he is in the habit of seeing on every hand, if he is artistic or romantic he will be indebted to that frontispiece; for, taking that as an index to the character of the work, if he does not want commonplace, he will lay it down respectfully and seek out some other amusement.
If the frontispiece has been drawn by a sympathetic artist, the interest of the reader is touched straight off and he turns next to the title-page.
Here he may find something to linger over, a dreamy vignette à la Turner, or an artistic commonplace which may suit his purpose. I prefer, as a book collector and a member of the Ex-Libris Society, a vignette either quaint and unique, or else one dreamy, soft, and suggestive, something of the style of the best editions of Sir Walter Scott, or of the old world of art, such as Walter Crane can give us, or a delicious Birket Foster, a Turner, or a Bewick; something which will tempt us, providing the binding is good enough, to paste our book-plate inside the cover and put it tenderly among the other kind friends of our solitude on our shelves, after we have read it—something, in fact, which may tempt us to order from the publishers a special copy bound in morocco, so that we may honour the artist who has delighted our eyes, as Esther did Ahasuerus.
As a good man who has gained an audience by a favourable introduction I would leave the author to do the rest. When once the reader has started on the story, he (the reader) does not feel grateful for any distraction. If the book is worth reading he wants to get right on with it without any interruption; if, however, it fails to interest him, he will lay it down after a few chapters and most likely send it on to some friend, or lend it out, or bestow it upon some charitable institution, or sell it with other works of the same kind to a second-hand bookseller.
In a scientific work or a book treating on special subjects which strictly require illustrations, so that the reader and author may be en rapport, the illustrations may be few or many as the text requires. This may be left to the author and the publisher entirely, because the reader lays aside his artistic sense of unity for the sake of the information he requires.
A properly illustrated book should be illustrated on every page. My ideal of such a book is to have to every chapter a head and tail piece, with marginal designs, running up and down wherever the text appears, in pen-and-ink or etching, for I hold that only outline drawing can harmonise with type as highly ornamental as possible. No tone-drawing should ever be introduced where type appears; but each chapter or poem ought to be separated by a full-page plate in tone, wood-engraving if possible, or the best process tone-work.