During the interval between 1440 and 1451, about which history records so little, Gutenberg may have printed many trifles. He could not have been always unsuccessful: he could not have borrowed money for more than ten years, without [p405] a demonstration of his ability to print and to sell printed work. It is probable that he had to postpone his grand plans, and that his necessities compelled him to begin the practice of his new art with the printing of trivial work. There is evidence that the branch of typography which is now known as job printing is as old as, if not older than, book printing. This evidence is furnished in the _Letters of Indulgence_, which have distinction as the first works with type-printed dates. [Illustration: Fac-simile of the Types of the Donatus of 1451. [From Fischer.]] Three distinct editions of the _Letters of Indulgence_ are known. The copies are dated 1454 or 1455, but are more clearly defined by the number of the lines in each edition, as _Letters_ of _30_, or _31_, or _32 lines_. Each _Letter_ is printed from movable types, in black ink, upon one side of a stout piece of parchment, about nine inches high and thirteen inches wide. The form of words is substantially the same in all editions, and all copies present the same general typographical features, as if they were the work of the same printing office. In all copies, the presswork is good; they seem to have been printed by a properly constructed press on damp vellum with ink mixed in oil. The types [p406] of the three editions have a general resemblance,[251] yet they differ seriously as to face and body. They were certainly cast from different matrices and adjustments of the mould,[252] and were composed by different compositors. In the edition of _30 lines_, the types of the text are on a body smaller than English, and those of the large lines are on Paragon body; in the edition of _31 lines_ the types of the text are on English body, and those of the large lines approximate Double-pica body. [Illustration: Paragon Body.] [Illustration: Pica Body.] [Illustration: English body.] [Illustration: Double-pica Body.] [Illustration: [from De la Borde.]] The types on Double-pica body are those of the _Donatus_ of 1451 and the _Bible of 36 lines_; the types on Paragon body are those of the _Bible of 42 lines_. The appearance of these types in the _Bibles_ is presumptive evidence that the printer of the _Bibles_ was the printer of the _Letters_. The small types are unique; they were never used, so far as we know, for any other work. The large initials may have been engraved on wood, but the text and the display lines were founded [p407] types. The illustration on the previous page shows that although the matrices were fitted with closeness, each type was founded on a square body.