The printing of these facsimiles has been done by letterpress, from zinc etchings made by the cold- enamel process; this insures fidelity and sharpness of type.
The pages were photographed on 8 x 10″ plates; enlargements to actual size were made by the photo- engraver. Slight discrepancies in over-all dimensions are unavoidable; in fact, existing good facsimiles made by letterpress, offset or collotype process differ as much as one-quarter inch from each other, in the depth of the page.
Wherever the pages are not perfectly square at the bottom, this is partly due to the original having been printed on dampened paper which has shrunk unevenly, and partly due to the difficulty encountered in photographing pages of a tightly bound volume that cannot, for obvious reasons, be removed from the library.
The copy in the GENERAL THEOLOGICAL SEMINARY having been trimmed considerably by the binder (10⅜ x 14 15/16″), the size of the present facsimile pages has been made to approximate that of the NEW YORK PUBLIC LIBRARY copy (12 x 15⅝″). The untrimmed page size of the original was close to 12½ x 18″, the gutter margin being 1¾″, the top margin 2¼″, the fore-edge nearly 3″, and the bottom margin nearly 4½″ wide.
The pages have been selected for their appearance and their contents; thus it was unavoidable that right-hand pages would appear in this book sometimes on the left, and vice-versa. It should be remembered, in case leaves are mounted or matted, that even-numbered pages in the original have the wide margin (fore-edge) on the left, odd-numbered ones on the right.
In the original, the running heads (red), the initials (red or blue), and the chapter indications and sub-heads (red) were added by the rubricator's hand. In a few instances (see Plate III) the chapter headings have been printed in red ink in the original, in a separate impression. This scheme was technically difficult and slow and was, therefore, abandoned in favor of handwork. An ingenious method of printing colors in perfect register was worked out by the Bible printer in the magnificent Psalter of 1457 (and subsequent editions) and in the Canon Missae of 1458.
Many of the existing (45) copies of this Bible show red strokes through all capital letters, added by the rubricator. In black reproductions these letters, therefore, look clumsy because the camera cannot separate the red from the black. In the GENERAL THEOLOGICAL SEMINARY copy these strokes are, fortunately, absent; thus the capital letters appear in their exact intricate design, as rarely seen in other existing facsimiles.
Texture and color of the original hand-made paper can only be approximated. A strong and somewhat thicker paper has been selected for these facsimiles so as to insure durability, especially in handling for display purposes.
The original has been printed in a deep, glossy black; the same kind of ink has been used in these reproductions. That, in conjunction with the slight indentation of the press, gives them an added value over those facsimiles made by a flat printing process (offset or collotype).
The elaborate painted decorations found in some copies of the 42-lie Bible, notably in the parchment copies (for instance that at the PIERPONT MORGAN LIBRARY) are additions by artists commissioned by the purchasers of the book and are not the work of the printers. To reproduce such pages (of which a few occur also in the GENERAL THEOLOGICAL SEMINARY copy) is technically very difficult, as the many pastel shades require multi-color printing. The only successful rendering of such art work appears in the complete facsimile edition of the INSEL VERLAG, Leipzig ( 1914) of which copies may be found in the larger libraries (for instance, the NEW YORK PUBLIC LIBRARY). It must be remembered, however, that the art work in no two copies is alike; that applies also to the rubricators' entries.