Preliminary studies -public sector

Why carry out a study?

The restoration process is often done after what is called “a preliminary study”. These studies can be more or less detailed and are destined to prepare us for a possible restoration.

The workshop carries out many of these studies, under order of the state, local authorities or museums. They help understand the historical background and the creation methods of the pieces. They also allow us to identify any problems regarding the conservation, and look at the cost of the restoration process.

Municipalities that wish to restore the stained glass of their church usually unaware of what has to be done. Where to start? Is it necessary to change all the bays? Should some of the pieces be restorer at the workshop? Will other skills be needed?

That is why the workshop frequently carries out these preliminary studies. They allow us to identify the problems and avoid risks due to the lack of experience of some of the technical services who might miss out crucial elements. Well informed of the delicate points, the municipality can work out a budget, search for funding if necessary and plan the phases of the restoration.

The workshop can also carry out a more detailed study often done in collaboration with the architect of the structure. The conservator prepares:

An assessment indicating the state of the various pieces (glass, lead, paint) and the quality of the workmanship. For each piece we determine if it’s the original, its age, and provide an opinion on its state of conservation. To evaluate the workmanship and the metalwork, the views of the architect, the builder and the locksmith are necessary.

For the works listed historical monument, a variety of opinions is even more important. Art historians provide valuable help and answer are questions concerning the dating, the filiation of the art work and their creators.

The “Laboratoire de Recherche des Monuments Historiques” answers the scientific questions if necessary: composition of the materials , alteration phenomena …

All this work is put together in a written document containing data and photos aiming to increase the knowledge of the stained glass and inform on its conservation state.

A proposal for intervention in response to the problems observed. Occasionally, for the restoration of a bay, a quick intervention is enough but that is not always the case.

Each situation is different. Thus, the conservator must note the contract specifications in a document that will indicate, window by window, panel by panel the interventions necessary.

The interventions can be ordered by priority from a conservation point of view but not necessarily if for instance a systematic restoration program has already been made (as the cathedral of Chartres for example).

With the study finished will be chosen a budget envelope according to the contract specifications so that once the budget goes beyond a certain amount a public procurement procedure can be launched.

Although all experts agree to say that the restoration is not a good that can be simply brought like any object, we are still waiting for this heritage to be officially recognized.

Getting close to the glass allows to develop protocols by testing various restoration techniques on small sections of the glass, particularly in sight of the cleaning and strengthening of the pictorial elements. The testing aims to determine the method that will solve the problem without damaging the glass. The help of the “Laboratoire de recherche des Monuments Historiques” is needed to validate the protocols for particularly delicate cases.

Finally, deciphering the glass is occasionally impossible because of the defects in the glass (missing paint, missing pieces of glass). The conservator must then find a solution in conformity with the original piece. Many ways exist: studying the traces left by the missing paint, interpreting the corrosion of the metalwork or using the potential symmetries of the picture. The paintings are sometimes done using a particular technique; it can then be necessary to experiment in order to master that technique and reproduce it. This type of research often shows the knowledge and skill of the glass painter or workshop.

The practical research is part of the “experimental phase” of the study.

The carrying out of studies concerning stained glass is an enormous job that calls for great concentration, wonderful patience and physical stamina… Whether he’s facing the glass and not being able to move, lifted by a cherry picker or balancing at the top of the scaffolding, a conservator is always gathering information. I would like to thank every single team, collaborator or intern that has endured either the cold or the uncomfortable positions high up with the pigeons… Especially, with great affection, those who form the “core”: Marie-Françoise Dromigny, Sylvie Poirson, Ludivine Rougeolle, Fabienne Buffet et Delphine Geronazzo whose final memoir « De la jumelle à la table lumineuse, les conditions d’observation des études préalables à la restauration des vitraux » has become an unavoidable reference.

I also wish to underline the remarkable work of Marie Françoise Dromigny, head of the stained glass department at the “Ecole Nationale Supérieure des Arts Appliqué et des Métiers d’Art”, who got deeply involved in the experimentation of various methods to determine the state of the stained glass. During the nineties when the municipality of Paris was encouraging the conservation-restoration of stained glass, Marie-Françoise re-evaluated and adapted her knowledge of traditional stained glass to the carrying out of preliminary studies. Task after task, we established the basics of observation still used today at the workshop.

Many other professionals take part and play un fundamental role in the elaboration of the studies and the restoration of the stained glass: conservators, art historians, scientists, local officials. Depending on their job they start, supervise, participate, support or finance projects of various sizes. Without their desire to protect our stained glass heritage, the restoration operations would not exist.