Deontology
of intervention on historical stained glass
The deontology standards applied in the conservation and restoration
of historical stained glass windows are, in general, the same
as the ones accepted for any other artistic materials. The
recommendations given in this page must be considered only
as general guidelines to be kept in mind. So, therefore, it
is advisable to consult the main deontology charters of intervention
on Cultural Heritage offered in this section.
• Interdisciplinary
work
Intervention on Cultural Heritage must be seen as a team work.
The whole process of intervention and all the decisions taken
should be supervised and approved by a team of professionals
on related areas, sufficiently trained and experimented, such
as architects, art historians, qualified restorers, chemist,
biologist, etc., as well as by the owners.
• Research and study
Any intervention on Cultural Heritage must be preceded by
a rigorous study of the main characteristics of the work.
These include the study of the main historic-artistical and
material-technical aspects. The process of restoration is
an exceptional and irreplaceable historical occasion for the
detailed study of the work. The most relevant results of this
study should be included in the Final Report of the intervention
and, if necessary, they should be published.
• Respect and preservation of all the intrinsic values
of the work
These include both the original values and the values acquired
by the work though its history. They can be artistical, esthetical,
iconographycal, documental, historical, pedagogical, scientifical,
economical, devocional, etc. The understanding, respect and
conservation of these intangible values of the work is a task
of the greatest importance and should be the responsibility
of all the members of the team in charge of the conservation.
• Respect and preservation
of all the material elements which constitute the work
These materials include glass, paint layers, lead net (as
well as copper foil and concrete), metal structures (ferramenta)
and the surrounded stone, brick or wooden frame. The respect
and conservation of all these material elements is also the
responsibility of all the members of the team in charge of
the conservation. Their removal or deterioration could cause
a serious damage to the aforementioned values.
• Minimal intervention standard
Any method or product used in restoration involves a potential
risk for the work, whose effects can often not be detectable
until years later. It is thus preferable to stop on time and
choose for a restrained and sensible restoration, giving priority
to an adequate conservation of the work. In the same way,
an excessive restoration can cause irreversible damage on
the work, which can lead to the loss of a some of its original
o acquired values.
• Maximal reversibility
standard
Any method, treatment or product used in restoration should
be easily removed in the future without causing damage to
the original materials. If we don’t know the performance
of a product or the effectiveness of a method in the long
run, it should be preferable to choose for a known safer one.
• Filling in missing
areas
This is one of the most delicate aspects of any intervention.
We should stop there where we lack any documentation and where
hypothesis and invention should begin. Any new addition should
keep a harmony and balance in colour, tone, texture, material,
form and scale with the original materials and should be signed,
dated and be easily recognisable. They should also stand discretely
on the background and never stand out more that the original.
• Cleaning
Cleaning is again a very controversial topic in the restoration.
Therefore, and as a general rule, the cleaning of stained
glass panels should be faced, firstly, as a conservation measure,
whose objective is to stop or at least slow down the process
of deterioration originated by the presence of dirt layers
or deterioration products and, secondly, as an attempt to
recover translucence. Any cleaning treatment is irreversible
and should be preceded by the realisation of discrete and
representative cleaning tests, starting gradually by the less
harmful methods and passing on, if necessary, to those potentially
more aggressive. Before any cleaning process, we should give
special attention to the possible presence of cold or flaking
paintings, ageing patinas and inscriptions.
• New materials
The use and application of new and modern materials on any
work should be preceded by an in-depth knowledge of their
properties, performance and longevity. Any new material added
to the work should be physically, chemically and aesthetically
compatible with the originals, don’t cause them any damage,
be reversible, adaptable to them as far as possible and don’t
deteriorate faster than them.
• Detailed documentation of the intervention process
Keeping up a detailed written, graphic and photographic documentation
of all the methods, materials and products used during the
intervention process, as well as the state of conservation
of the work before, during and after the intervention, is
a necessary and unavoidable task. The correct conservation
of this documentation, which provides a highly valuable information,
is also responsibility of the restorer.
• Preventive conservation
The correct conservation of any work should be a priority
and a preferable choice to direct restoration. Today, the
most effective conservation measure is the protection of the
work with an adequate isothermal outer glazing system, whose
correct working should be regularly supervised. Besides, the
monitoring of all the possible deterioration agents, like
the intensity of the UV and IR radiations coming from natural
or artificial light, the presence of pollutant gases, the
temperature and relative humidity levels and changes, the
ventilation of the building, etc., can be of greatest importance.
• Regular maintenance
and inspection
Any historical stained glass window should undergo regular
supervision and maintenance inspections in order to control
on time any anomaly which may arise and prevent further deterioration.
These inspections, which should be carried out by experimented
conservators, are the most effective way to guarantee the
better conservation conditions of the work and avoid unnecessary
restorations.
_________________________________________________________________________________________
Links to the main charters on C&R
Guidelines for the conservation of
ancient monumental stained and painted glass
ICOMOS – CVMA, Amsterdam, 1989.
(English, French, German)
Guidelines
for the Conservation and Restoration of stained glass (Second
Edition)
CVMA - Nuremberg 2004
The
Athens Charter (Carta del Restauro)
I
International Congress of Architects and Technicians of Historic
Monuments, Athens, 1931.
Convention
for the Protection of Cultural Property in the Event of Armed
Conflict
The
Hague, 14 May 1954
The
Venice Charter
II
International Congress of Architects and Technicians of Historic
Monuments Venice, 1964.
The
Declaration of Amsterdam
Congress
On The European Architectural Heritage
Ámsterdam, October 1975
European
Charter of the Architectural Heritage
Congress
On The European Architectural Heritage
Amsterdam, October 1975
The
Conservator-Restorer: a Definition of the Profession
ICOM,
Copenhagen, 1984
Code
of Professional Ethics
ICOM,
Buenos Aires, Argentina, 1986; Barcelona, Spain, 2001.
Guidelines
for education and training in the conservation of monuments,
ensembles and sites
ICOMOS,
Colombo, Sri Lanka, 1993.
Second
Protocol to the Hague Convention for the Protection of Cultural
Property in the Event of Armed Conflict
The
Hague, 26 March 1999
The
Charter of Krakow
European
Commission, Krakow, 2000
|
