The knowledge required to become a professional book conservator ranges from bookbinding history to materials science. Book conservators must also be skilled in the techniques of bookbinding and identification of deterioration to the components of a book before undertaking conservation work. This breadth of experience is encompassed within in the code of ethics adopted by many professional conservation bodies in Europe and the UK.

"The Conservator-Restorer is a professional who has the training, knowledge and skills, experience and understanding to act with the aim of preserving cultural heritage for the future...."(ECCO, 2002).

Taking bookbinding leather as an example, the conservation process has several stages. This includes; skills in examination techniques to identify the type of leather and causes of deterioration; determining the conservation proposal; and performing conservation standard leather treatments and structural repairs to degraded leather bindings. Current initial and mid-career training in the UK is not equipping book conservators with the necessary knowledge and skills for making that all important 'informed decision' on the conservation needs required for this type of bookbinding. This paper will consider two current influences on the shortcomings in the knowledge and skills required for the conservation of leather bindings: gaps within education and a general confusion about leather.

Educational centres will always respond to demand from conservation employers. Currently employers are concentrating their resources towards non-interventive practises such as housing and environmental storage conditions - both important aspects of preventative conservation practice for long term stability of leather bindings. In the case of acid decay (red rot) damaged vegetable tanned leather bindings, evidence has shown a causal link between the storage and display environment and the longevity of the 19th century manufactured vegetable tanned binding leathers as discussed by Florian (2006). Improved storage conditions can dramatically slow the rate of deterioration. Of equal importance is interventive conservation to meet the conservation needs of damaged leather bindings that are expected to be consulted, having a sound structure and covering material. The downplaying of interventive skills is creating a generation of unskilled practising conservators who apply to work in public institutions and private practice with limited technical knowledge and hand skills required to undertake high quality interventive work when required.

There is general confusion within the profession that bookbinding leather and its conservation needs is too broad and difficult a topic to understand. This perception seems to be due to 'the literature', as this is where conservators usually go for information when training and advice is not available. Firstly, most relevant literature from conservation research and manufacturers is generally not written for conservators. They are written for a technical readership with a familiarity of some fundamental, complex concepts and terminology of leather such as; the chemistry of tannages and dyes; theories of chemical and physical deterioration mechanisms as leather degrades - theories that share some similarity with the deterioration of other materials such as paper. Most book conservators are not equipped to understand this literature, as these concepts are not part of initial conservation education and professional development training. This has resulted in a culture of mistrust that if information is not clearly understood then somehow the manufacturer or supplier is keeping something from the conservator.

When relying on the literature for guidance there is also difficulty in determining the suitability of bookbinding leathers for conservation standard structural repairs. Bookbinding leather has a long history of published research dating back over 150 years. The most recent published investigation to identify and realise durable bookbinding leather for bookbinding and book conservation purposes being the European Commission Craft Programme, referred to as The Craft Leather Project. A consortium of tanners, bookbinders, conservators and leather scientists were brought together from Germany, Greece, Italy and Great Britain with

"the primary aim....to develop a range of bookbinding leathers having chemical properties to give resistance to acidic polluted atmospheres.... together with the physical characteristics demanded by bookbinders"(Thomson 2003:65).

Samples were taken from seventy-one commercial tanners and leather dealers in Europe, and the study included calf, goat and sheep skins tanned using vegetable tannins, semi-chrome, alum, semi alum and full chrome. In the UK both J. Hewit & Sons and Harmatan & Oakridge Leathers developed improved vegetable tanned leathers for bookbinding and conservation purposes as a result of recommendations from this project.

A consequence of this confusion via the literature regarding new bookbinding leather has encouraged the use of alternative materials. For example, the practice of replacing degraded vegetable tanned leather components of a binding with large strips of Japanese repair paper or alum tawed (semi-tanned) leather for rebacking. This is similar to the issue of using Tyvek© to replace the spines of vellum bindings. While these alternative materials are being used with confidence within the conservation profession there are two problems. Firstly, both materials require further research into their long term chemical and physical properties such as that observed by Vest (1999) in the analysis of the deterioration of white tawed leather. The second problem is the permanent alteration of the character of the binding due to the different physical properties of these materials in conjunction with the original covering material. The aesthetics and mechanics of the binding are being changed by the use of alternative materials that can not always be easily reversed. Using the example of the conservation of 19th century vegetable tanned leather bindings it is difficult to find published evidence against using some of the modern vegetable tanned bookbinding leathers for book conservation repair. Coupled with improved storage and handling when returned to the collection, the longevity of the conservation work done using modern leathers is a vast improvement from previous repairs undertaken in the 19th and early 20th century.

Leather treatments are another area of confusion within book conservation literature. There is a documented history of now inappropriate leather consolidants and surface coatings that leave the book conservator unsure of which treatments to trust (see Haines, 2002). The newest leather treatment has been developed by Dr. Anne Lama (2012) at The Leather Conservation Centre, Northampton in co-operation with Dr. Jeffry Guthrie-Strachan of The Institute for Creative Leather, University of Northampton. This should be another option for the treatment of acid decay damaged vegetable tanned binding leather available to the book conservator. This like any leather treatment can only be used if the constituents of the treatment are understood by the conservator for its short and long term effect on the physical and chemical properties of the leather. Only through clear and concise literature and training in correct use can this, or any leather treatment, be used by the conservator with confidence that they are slowing the rate of deterioration in leather.

Currently I teach students and practising conservators and restorers with limited knowledge of the lifecycle of bookbinding leather, with emphasis on the retention of bookbinding leather as part of the intrinsic value of the binding. There is a desire amongst student and book conservators for more accessible information on the chemistry of vegetable tanned leathers and chemical treatments such as consolidants and surface coatings. Some of this information must come from the manufacturer/supplier, some must be sought out by the book conservator using the material science knowledge that they have to understand a complex material like leather. The expectations of students and professional book conservators need to be articulated to influence improvements in education and training to ensure the use of appropriate treatments and materials.

The discipline of Book Conservation does have an 'arsenal' of published techniques for the conservation of leather bindings. In particular, for those bindings from regularly accessed collections requiring interventive conservation work. Book conservation has come a long way when reading through the list of techniques and materials as listed in a short article on book restoration by Middleton (1994) to more recent surveys from the United States such St John (2000) and Baker and Dube (2009). Both highlight the much broader range of techniques and materials currently being used in book conservation. For the conservation of leather bindings, the informed choice of the most suitable conservation treatment and repair techniques should be based on a rigorous assessment of the specific conservation needs underpinned with appropriate training, knowledge and skills.

As a profession, book conservation needs to be better equipped to identify the specific conservation needs of leather bindings to decide on the most suitable repair materials and chemical treatments. Students and professional book conservators require better education and training in understanding the lifecycle of bookbinding leather from manufacture to conservation. This will go some way towards reducing the confusion around leather and ensure book conservation is focused on retaining the character of each binding based on knowledgeable judgement and skilled work.

Discussion is welcome.

References

Baker, W. and Dube, L. (2009) Identifying standard practices in research library book conservation, Library Resources & Technical Services, vol. 54, no.1, pp.21-35. [Online] Available: https://kuscholarworks.ku.edu

European Confederation of Conservator-Restorers' Organisations, E.C.C.O. (2002) Professional Guidelines. Promoted and adopted by its General Assembly, as adopted by The Institute of Conservation, United Kingdom. [Online] Available: www.icon.org.uk

Florian, M. (2006) The Mechanisms of deterioration in leather in Conservation of leather and related materials, Kite, M and Thomson, R. (ed.) London: Butterworth-Heinemann, pp.36-57.

Haines, B. (2002) Surface coatings for binding leathers. Northampton: The Leather Conservation Centre.

Lama, A et al. (2012) Investigation of Acid-Deterioration in Leather Leading towards Finding a Suitable Product for Treatment. Press release. [Online] Available: https://jeffpeachey.wordpress.com/

Middleton, B. (1994) A century of developments in restoration binding, New Bookbinder, vol.14, pp. 66-69.

St. John, K. (2000) Survey of current methods and materials used for the conservation of leather bindings, The Book and Paper Group Annual, vol.19, pp.131-142. [Online] Available: https://cool.conservation-us.org

Thomson, R. (2003) Towards a longer lasting leather, Bookbinder: The journal of The Society of Bookbinders, Vol.17, 2003, pp.65-70

Vest, M. (1999) White tawed leather - aspects of conservation In Preprint from the 9th International Congress of IADA, Copenhagen, August 15-21. [Online] Available: https://cool.conservation-us.org

Karen Vidler - is a qualified bookbinder and book conservator, trained at both Guildford College and West Dean College. She has managed a small conservation practice, Book Conservation Services, since 2006. Her work has included establishing a Book and Paper Conservation Studio for The Leather Conservation Centre, Northampton as well as being a Book Conservator with the V&A Museum and The National Archives. She teaches the conservation of leather bookbindings to students of conservation and qualified Conservators in Europe and the UK. She is also pursuing ongoing research into an improved understanding of the deterioration of bookbinding leathers. Karen has a web site at www.bookconservationservices.co.uk

Editor's note - Karen refers to 'The Craft Leather Project' which J Hewit and Sons was involved in. A summary of the results and summations of this project can be read or downloaded as a PDF file at: www.hewit.com/download/fs-craft.pdf

Currently Hewit's production of Chieftain Goat and Archival BV Repair Calf are carried out using the archival processes described in this document. Please do not hesitate to contact us or have a look at our web site if further information is required.