- Plating [see Tanselle, ‘Treatment’ cit., pp. 43-51: “Variation in furniture width” and pp. 54-57 “Plating evidence’]. From the middle of the Eighteenth century an increasing number of successful works had their original setting copied in casts from which metal plates were made; see Gaskell, A New Introduction to Bibliography cit., pp. 201-205. Although experiments are known to have taken place in Holland in the Seventeenth century, the invention proper is generally attributed to William Ged in 1739, see John Carter, ‘William Ged and the Invention of Stereotype’, The Library, s. 5, vol. 15 (1960), pp. 161-192, with further instalments in vol. 16 (1961), pp. 143-145; vol. 18 (1963), pp. 308-309. Recently however controversy has arisen around the theory advanced by Paul Needham and Blaise Agüera y Arcas, according to whom the Gutenberg Bible and other incunabula were printed with lines of type cast in sand-moulds, with the invention of moveable type coming only a few years later. A full bibliographical account of the research still has to appear; for the moment see the report in the Princeton University Chronicle [link to http://www.princeton.edu/pr/pwb/01/0212/ ] and the review by Stephen O. Saxe in the Apha Newsletter, n. 143 (Spring 2001) [link to www.printinghistory.org ]. After the introduction of flong (paper) moulds in Lyon in 1829, it should be noted that if, as often happened, the first impression of a work was done directly from type and the successive ones from plates, a degree of shrinkage should be perceptible and needs to be noted in the description. With use plates become increasingly battered around the edges and thus are easily recognised, while all the copies made from the same set of plates in a single printing session are considered an ‘impression’. Stereotype plates were often made in duplicate or multiple sets, either because for a best-seller a set was sent across the Atlantic to the American or British publisher, or because, if a large number of successive impressions were called for, when the first set wore out, it was possible to employ the duplicates. Plates can be corrected and modified, and therefore it does occur that a series of changes introduced into the first set suddenly disappear when the reserve set comes into use; see Matthew J. Bruccoli, ‘A Mirror for Bibliographers: Duplicate Plates in Modern Printing’, Papers of the Bibliographical Society of America, vol. 54 (1960), pp. 83-88; Peter L. Shillingsburg, ‘Detecting the Use of Stereotype Plates’, Editorial Quarterly, vol. 1, n. 1 (1975), pp. 2-3; Idem, ‘Register Measurement as a Method of Detecting Hidden Printings’, Papers of the Bibliographical Society of America, vol. 73 (1979), pp. 484-488; James L.W. West III, ‘The Bibliographical Concept of Plating’, Studies in Bibliography, vol. 36 (1983), pp. 252-266.

- Pointholes (Pinholes) [see Tanselle, ‘Treatment’ cit., pp. 24-28]. On all hand-worked presses the exact register between outer and inner formes was achieved by placing a number of pins, usually two but in early incunabula or in complex printing operations (red/black, music) the number could be higher, on the tympan. When printing the reteration the puller took care to place the holes in the sheet left by the previous passage under the press on the pins. Unfortunately pins were customarily placed in correspondence with the central fold in the sheet, so that their traces have been obliterated by the sewing and binding operations. See Martin Boghardt, ‘Pinholes in Large-format Incunabula’, The Library, s. 7, vol. 1 (2000), pp. 263-289, followed by Lotte Hellinga, ‘The Interpretation of Measurements of Pinholes and Analysis of Ink in Incunabula’, The Library, s. 7, vol. 2 (2001), pp. 60-64.

- Press Figures [see Tanselle, ‘Treatment’ cit., pp. 43-51]. In the Eighteenth-century, mainly in the English-speaking world, books are often found with very small figures at the foot of certain pages. For a long time ignored by bibliographers, in more recent times they have received more attention; cfr. the summary of the previous literature in Kenneth Povey, ‘A Century of Press Figures’, The Library, s. 5, vol. 14 (1959), pp. 251-273. Their interpretation remains nonetheless a problem, since it is not always clear whether they refer to type-setting or to press-work, and indeed there is no guarantee that they meant the same thing at all times to all men.

- Press Runs and Performances . No truly authoritative study of known press-runs exists, since the relevant information mostly comes from outside the book itself and has to be painfully garnered from archive documents and other secondary sources. What we also lack is a proper reflection on the varying levels of authority provided by such sources. A contemporary letter tells us that the Gutenberg Bible had a press-run of approximately 180 copies and, up to the introduction of the two-pull press, runs seem to have stayed low, in the order of 200-300 exemplars, more due to the inability of the market to absorb the output than because of the limits of the technology. From the late 1470s runs increase substantially to a thousand and more copies. In an age, however, in which the major printing cost was represented by the paper, except for garanteed bestsellers, it was not economical to tie up capital in an edition of more than 1500 exemplars and many runs were considerably less. References to known print-runs appear in most standard histories of the book (for example Febvre-Martin, L’Apparition du livre, ed. 1971, pp. 307-313), but caution is required since the exceptional tends to be cited more often than the usual. DE" lang="DE">Some known figures, albeit without a clear distinction between nuclei of copies registered in warehouse inventories and print-runs true and proper,  are listed in Uwe Neddermeyer, Von der Handschrift zum gedruckten Buch: Schriftlichkeit und Leseinteresse im Mittelalter und in der frühen Neuzeit: Quantitative und qualitative Aspekte (Wiesbaden, Harrassowitz, 1998, vol. 2, pp. 752-770). Another potentially contentious issue is the daily production of a press, which could oscillate considerably according to the quality of the work required, see for instance the earliest day by day record so far published, for the Cambridge University Press in 1699-1702 in D. F. McKenzie, The Cambridge University Press, 1696-1712: A Bibliographical Study (Cambridge, Cambridge University Press, 1966, vol. 1, pp. 132-133), where output varies between 700 and 1700 sheets per day, though we do not know the number of hours involved. A useful discussion and summary of the early claims and indications, though not equally sound in its conclusions, appears in Michael Pollak, ‘The Performance of the Wooden Printing Press’, The Library Quarterly, vol. 42 (1972), pp. 218-264.

- Presses (One-Pull and Two-Pull) . Incunabulists have long known that early presses could not cope with more than a half-sheet of paper at a time and sometimes less; see McKerrow, An Introduction to Bibliography cit., pp. 57-63. When formats were quarto or less, it was convenient to divide the sheet before printing and impress the half-sheet. Recent research by Lotte Hellinga on watermark distribution in early incunabula has discovered that whole sheets were used consistently for the first time in Rome in 1472 by Georg Lauer; see ‘Press and Text in the First Decades of Printing’, in Libri tipografi biblioteche. Ricerche storiche dedicate a Luigi Balsamo, a cura dell’Istituto di Biblioteconomia e Paleografia, Università degli Studi di Parma (Firenze, Olschki, 1997, vol. 1, pp. 1-23). The logical deduction is that a new sort of press, one in which a whole sheet could be printed with two pulls in rapid succession, had been discovered. One-pull or two-pull printing in a folio format can be established by a variety of means, for instance by recognising first and second forme printing or by variants in different pages that fail to match up. A curious case involving an upside-down page is described by Neil Harris, ‘Una pagina capovolta nel «Filocolo» veneziano del 1472’, La Bibliofilìa, vol. 98 (1996), pp. 1-21.

- Printing Style and Habits . Bibliographers often struggle to decide where a book lacking or with an incomplete imprint was produced and likewise cataloguers, faced with a damaged or incomplete copy, often have to study the typography in order to guess and approximate date and place of printing, before beginning research to identify the edition. Any and every guidance as to how to overcome these difficulties is severely empirical, i.e. look at lots of books. Inevitably the more books one has seen, the easier it becomes to solve the problem, and an experienced person generally has no difficulty in dating and placing printed manufacts with a certain precision. A succinct but useful series of hints about typographical style can be found in Richard A. Sayce, ‘Compositorial Practices and the Localization of Printed Books, 1530-1800’, The Library, s. 5, vol. 21 (1966), pp. 1-45, reprinted with addenda and corrigenda, Oxford, Bibliographical Society-Bodleian Library, 1979. The reception and critical history of Sayce’s fundamental essay is described by Frans A. Janssen, ‘Layout as a Means of Identification’, Quarendo, vol. 25 (1995), pp. 46-58. For an interesting evaluation instead of how quotation marks were employed in Eighteenth-century printing and on the Continent, also as a way of distinguishing the true origin of books printed under a false imprint, see C.J. Mitchell, ‘Quotation Marks, National Compositorial Habits and False Imprints’, The Library, s. 6, vol. 5 (1983), pp. 359-384.

- Proof-Reading. The classic account remains Percy Simpson, Proof-Reading in the Sixteenth, Seventeenth and Eighteenth Centuries (London, Oxford University Press, 1935, and reprints), while a more recent round up of examples of proof sheets recovered or discovered remains a desideratum. An interesting recent discovery is a Florentine document of 1598 which stipulates that the typographical composition is also to be read ‘in the lead’; see Gustavo Bertoli, ‘Organizzazione del lavoro tipografico, lettura in piombo e correzione nei preliminari del contratto fra Scipione Ammirato e Filippo Giunti per la stampa delle Istorie fiorentine’, La Bibliofilìa, vol. 97 (1995), pp. 163-186.