An excerpt from The Restoration of Leather Bindings
The craft of bookbinding encompasses a wealth of procedures, techniques, approaches, and skills. The celebrated title The Restoration of Leather Bindings by Bernard C. Middleton provides definitions, tools, materials, instructions, and more for how to restore bindings. One section of the book discusses the restoration of antiquarian books, and more specifically, the restoration of vellum bindings. See what Middleton says about cleaning and coloring vellum covers. He gives some great tips to remember!
Cleaning. Minor cleaning of vellum covers can be done by dry means, but if the cleaning is to be really effective it is necessary to use aqueous solutions; in general, these are not recommended and should be employed only by experienced restorers. Saddle soap or other high-quality soaps can be used, but a cardinal rule, if the stability of gold tooling and ink inscriptions is not to be adversely affected, is to keep pressure and moisture to a minimum, so soapy swabs should be damp rather than wet, and rinsing with damp cotton wool should follow quickly. Milk is sometimes used for the cleaning of vellum because the fat content helps to obviate roughening of its surface, but there is some objection to this on the grounds that in an unsatisfactory environment it may give rise to microbiological problems. Ink inscriptions are best avoided altogether and certainly any rubbing should be very light and brief because many are easily marred or even completely removed.
Vellum-covered Boards. Technically, vellum bindings are treated in much the same way as leather-covered ones, but a few points are worth mentioning in relation to rebacking. One is that if, as is often the case, the old vellum is lined with paper which is loose, the new vellum should underlie both the old vellum and its paper lining on the sides, otherwise the new vellum is likely to show through darkly when the old vellum is stuck down on to it. It is easy inadvertently to position the new vellum between the two layers.
Much modern vellum has little stretch, so it is often quite difficult to form it over prominent rasied bands and to make it stick between them, so tying-up cords may need to have considerable tension. The cord may also need to be kept in position for several hours, and there is no problem about this because there is no danger that the old vellum on the sides will be discoloured by contact with the wet new vellum which is certainly a hazard in the case of leather-covered bindings. If the raised bands are very large, as they tend to be on old Dutch books, and the new vellum is intractable even after much soaking with paste, some creasing of the vellum on the sides may results, but if these cause unsightly ridges they can be sliced off when dry without detriment to the strength of the work. The surface of the new vellum should be scratched and scraped where it underlies the old vellum on the sides and the spine, if any, so that firm adhesion with paste of PVA is aided. Pressure can be protracted unless there is danger that blind tooling will be obliterated, in which case the book can be put between backing boards in the lying-press after the first few minutes so that pressure is then localized at the edge of the old vellum.
Colouring of the new vellum can be done very satisfactorily with spirit stains, the technique being to apply the stain with a swab of cotton wool and then to rub it almost immediately in a circular motion with clean cotton wool as the stain dries, which it does fairly quickly. If this is done too soon the stain may be removed, and if it is too long delayed streaking may result. Staining is best done on the book so that local variations of tone and density can be made to match the ageing of the original vellum. At one time, much green vellum was used, especially on blank books used for estate accounts, and the like. If matching vellum is not available one’s own green staining should be done before the vellum is pasted on so that inaccessible parts do not show white, and then local colouring can be done at a later stage.
The headcaps on many antiquarian vellum bindings were made by tying cord around the fore edge of the book and the back of the headband, and then bending the vellum back against the cord so that the vellum is at right angles to the line of the backbone instead of knocking the vellum over on to the headband form a conventional cap. This better suits the nature of the material.
If the boards are warping outwards very badly it is likely that the only satisfactory remedy will be to remove the edges of the boards and then replace the vellum as described on page 184 for leather-covered bindings.
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