Turning now from the tactile to the visual elements of the fine book, we shall consider, first of all, that fundamental factor of all books, the text-page, upon the form or "layout" of which all other typographic elements must, to a large extent, depend. The text-page is of primary importance because by its rightness or wrongness a book must stand or fall.
The elements of the text-page that call for consideration may be grouped under three heads: first, _Form_ (the proportions--width to height--of the type-page and the balance of the rectangle of type with the rectangle of paper); second, _Space_ (the ratio between the areas of the type-page and the paper-page); third, _Tone_ (the tonal value of the type mass and the relation between its tone and the white area of the margins). In the perfect text-page all these elements may be observed in nice adjustment, severally and mutually.
There are those who contend that a proper relation of margins to type-page may be arrived at by employing ratios identical with those to be found in the well-proportioned pages of the early printers. Others declare that correct margins can be created by the application of an arithmetical or a geometrical formula. It can be admitted that such procedures are, at least, _safe_; that is to say, the danger of malproportioned margins will be avoided. But neither the method nor the result can be ideal for the simple reason that, while providing for the factors of form and space, they fail to provide for the factor of tone. It should be obvious that a rectangle of black type, with no space (leading) between lines, and a rectangle of the same shape and size printed from light-face type and generously leaded call for different margining.
All of this may seem to be supervacaneous, but the stubborn fact remains that no one of the factors set forth above can be ignored. It is perfectly true that the accomplished book designer will compass the desired end through a sagacious application of his knowledge and taste, but we are concerned here with presenting the elements of the ideal book and it is therefore essential that _all_ the elements, no matter how much the initiated may take some of them for granted, should be, for the benefit of the layman, categorically enumerated.