The cover of the Voynich MS is of blank parchment that does not have any indication of its origin (year, title or author). The >>Beinecke library description of the Voynich MS calls the cover of the MS a limp vellum cover of the 18th - 19th C. This tells us that the cover is not original to the MS, and in all likelihood replaced an earlier cover.
In July 2014 eraser crumb samples were taken from approximately 10 places in the MS, and on my recommendation also from the cover. These were sent to a team of the University of York in order to identify the species of the animal from which the parchment was made. This is done by extracting protein from the samples and matching them with samples from known species (1). While for all folio samples the species was identified as 'cow', the cover sample could not be matched to any species. However, in November 2014 the professional parchment maker Jesse Meyer of Pergamena identified that the cover parchment is made of goat skin (2).
While the cover is described as a limp cover, this is not what it was originally made to be. It used to be stiffened by filling materials. The cover also shows remnants of paper pastedowns (see right-hand picture above) that have been removed. The pastedowns and the filling materials were most probably removed by Wilfrid Voynich himself, shortly after he acquired the MS. Possible reasons for this are explained below.
The cover of the Voynich MS is very similar to that of other manuscripts that Voynich acquired at the same time, e.g. a Boccaccio MS now in Chicago, and a Petrus Candidus MS now in Harvard (3). In these manuscripts, new pastedowns have been added. In addition, in 2014 I learned from one of the MS experts of the Vatican Library, that the vast majority of all MSs among Vat.Lat.11414 – 11709, which also came from the same collection sold by the Jesuits in 1912 (4), have identical covers, and she confirmed that the one of the Voynich MS is quite similar. Since then, some of these MSs have been digitised and are visible online, e.g.: >>Val.lat.11458 or >>Vat.Lat.11504. These images clearly show the common type of binding.
This rebinding is briefly mentioned in the catalogue of Vat.Lat. 11414-11709, written in 1959 by Mgr. J. Ruysschaert (5), where we read that many of these manuscripts have been rebound by the Jesuits of the Collegium Romanum, though he does not indicate that this concerned almost the complete collection. Thus, we know that the present cover of the Voynich MS was added (presumably replacing an earlier one) by the Roman Jesuits, i.e. after the MS was received by Kircher.
There are insect holes in the first and last folios of the MS. As pointed out by the conservators who inspected the MS for several hours in the Folger Library in Washington in November 2014, these insects are not at all interested in parchment, but in wood. This led to the conclusion that the original binding of the MS almost certainly had wooden boards. The woodworms just nibbled at the first and last pages and the location of the wormholes matches well with the places where the insects could move in and out of this cover. From discolouring on the first and last folios it was furthermore concluded that these wooden boards were covered by tanned leather (see note 2). Interestingly, Manfred Staudinger, who has been researching the account ledgers of Rudolf II preserved in Vienna, once remarked that the Voynich MS could hardly have been owned by Rudolf II, because it should have had a very different binding. This objection has now been explained.
Research performed by staff of the Historical Archives of the Gregorian Library in Rome has been recorded in their blog (6), and this tells us that the MS collection was described, sometime in the 18th Century, as “old books infested by worms”. The manuscripts were subsequently sent to a binder, where they were rebound, usually without having to replace the old stitching. The Boccaccio MS seems to have undergone a similar fate, as it has quite similar insect holes as the Voynich MS (7).
It was mentioned above that the pastedowns were probably removed by Voynich. We can't be certain, because the few items visible in the Vatican library also appear to have damaged pastedowns. However, the habit of Voynich to search in covers of old books has been recorded in Zimmern (1908) (8), who writes:
[Voynich] knew that when a book is bound in vellum it may hide in its heart unexpected treasures. Hence it was reserved for him to make the quaintest and most valuable discoveries in the backs of the old bindings. Voynich never discards a book until he has stripped it of its cover. Here often the most priceless finds are made - a fact few even among book lovers know. For in the days before commercial cardboard was known, to stiffen the backs and sides of a book everything that was available was used and pasted together to make a compact mass. Hence the binder packed in much then held mere waste stuff, now often worth its weight in [5-pound] notes.
When the book came into the possession of Kraus, the cover was largely detached. Following is a picture of the stitching of the MS (9), which was also intensively studied in 2014:
This shows a combination of both very old binding details and a few modern repairs, for on the inside back cover we may read:
P Some signatures at beginning and end resewn with Irish linen thread
P Vellum cover attached with leather thongs and vellum guards added at beginning and end
The abbreviation HLH refers to Hellmut Lehmann-Haupt, a famous bibliographer who was also a consultant to H.P.Kraus (10). Below the number at the bottom (presumably a catalogue number) there appears to be another erased number.
The leather thongs were added in the 1960's, and glued on top of the old, possibly even original (fifteenth century) thongs, that were made from some kind of fiber. This was a repair made in order to stabilise the binding. The white thread visible in these figures also dates from the same repair. There are remanants of an old paper lining, and the conservators also detected very tiny fragments of leather attached to this area.