the Past in Colour
is endemic amongst professionals involved in the conservation
and repair of historic buildings, including building archaeologists
and historic paint analysts in particular. Fortunately, it is
also a trait possessed by the owners of many buildings in equal
abundance. The secrets held by the layers of paint which cover
so much historic fabric provide tempting clues to the way the
building or structure appeared to previous generations. The problem
is how to unlock this information.
presentation of architectural compositions such as the interior
of a room seems confusing. The elements created in one period
are presented according to the tastes of successive owners and
occupiers, and the colours used by one generation may effect a
very different character from that originally envisaged. Highlighting
one surface in a particular way can also have a substantial impact
on its relationship with other elements, affecting the architectural
composition dramatically. Wall paintings and decorative effects
such as trompe d'oeil wood graining and marbling may also have
been used in the past, and there may have been physical alterations,
such as the introduction or removal of panelling or a fireplace.
how the room has changed can be difficult, not least because decorative
schemes overlay each other, and can even co-exist in the same room. The
key to unravelling this information is an architectural paint
investigation. This process, which should be seen as an archaeological
exercise, involves careful examination of all the available evidence,
including archival records and the paint layers themselves, to
build up a picture of the decorative evolution of the surfaces.
However, investigations are often targeted to shed light on the
decorative treatment in one specific period.
gathered in this way may be used to recreate a decorative scheme
of a particular period, or it may simply be recorded for posterity.
Where conservation repairs or investigation work necessitate the
removal of the historic paint layers, as is sometimes necessary,
the paint analysis and the archived samples may serve as the only
surviving evidence of its decorative history, providing vital
information for future generations.
research is an important component of a paint research project
as it will give a context to the findings and it will help to
determine where samples should be taken. Historic bills, contemporary
descriptions or illustrative material all serve as useful sources
of information. Such records might be found in archives held at
the historic property itself or in local or national depositories.
Oral history can also provide invaluable information: those who
lived or worked at the property for many years often have insights
into earlier uses and alterations not immediately apparent.
essentially involve the examination and analysis of surviving
paint layers by a variety of different techniques, including cross-section
analysis, and scraping back to expose the various layers.
rule of thumb when taking samples is that the greater the number
and the larger the sample, the more information will be retrieved.
However, this approach must be balanced against the sensitivity
of the fabric. In the case of an interior, samples would usually
be taken from each of the architectural features within a room
and any sub-component that might have been decorated in a different
manner. In a complex entablature for example, certain elements
might have been gilded or highlighted in contrasting colour, so
to gain a true understanding of how it was decorated, it would
be necessary to sample all its constituent mouldings, and because
each element is quite small, several small samples might be required.
On flat surfaces such as large expanses of wall it may be possible
to take larger samples, but they should still be taken from a
variety of locations. This reduces the chance of sampling an unrepresentative
area such as a wall where soft distempers have been washed down
prior to repainting, or an area affected by a physical alteration.
Where analysis reveals that substantial paint stripping has been
carried out in the past, the results may be sketchy
and extrapolation of the results may be required.
On an exterior
surface which has been exposed to the elements, the chance of
finding that previous layers have been lost is much greater, and
sampling must focus on very specific points where old paint layers
are most likely to survive.
the samples are set in resin blocks, ground down to expose a cross-section
through the paint layers, and polished. They are then examined
in both incident and ultraviolet light to develop an understanding
of the sequencing of decoration as well as the materials employed
in their execution. Microchemical tests are also useful for determining
the nature of the pigmentation and medium identified in cross-section.
Further commonly available techniques for pigment analysis include
polarising light microscopy, which helps to identify many of the
mineral constituents of an inorganic pigment; electron dispersive
X-ray spectrometry (using an electron scanning microscope) or
Raman spectroscopy, both of which can determine the elemental
composition of the sample. Gas chromatography-mass spectroscopy
can also be employed to give more information on the medium involved
in a particular decoration.
of materials is important for gaining an understanding of the
appearance of a decorative application and how it may have deteriorated
over time. But certain materials, particularly pigments, also
have dates of manufacture or introduction associated with them.
When comparing these date markers with documentary evidence it
is possible to establish a picture of how the room has changed over
is a relatively new area of conservation, not everyone knows how
to commission a paint analysis programme in order to reap its
full potential benefit. The most common misunderstandings concern
the timing of paint analysis within a conservation project. If
the investigations have been initiated strictly to gain further
information on the development of a room as an end in itself,
and the surfaces concerned are not about to be stripped, the research
can proceed at its own pace without many outside constraints.
If, however, the results of the analysis will have a role to play
in the planning of a conservation project or in the redecoration
of a room, its role in the programming is more crucial. As paint
investigations can be thought of as the archaeological portion
of the project, it becomes clear that this work has to be done
prior to actual conservation and building work. It should provide
the first piece in the puzzle, shaping the approach taken to the
conservation of the building and the way in which the fabric is
(above left) taken from the ceiling fish motif (above right) in the foyer
of the Apollo Theatre, London. Currently embellished with
details in gold paint, the sample confirms that the detail
was originally entirely silver, with varnished aluminium leaf.
The illustration at the start of the article shows another
fish from this remarkable 1930s interior, which is now known
to have been similarly altered.
it is worth bearing in mind when planning a conservation project
that architectural paint analysis is a service offered by a relatively
small group of properly trained specialists, and it may not always
be possible to find one free at short notice. It is advisable
to assess the need for paint analysis at the earliest opportunity.
To gain the
greatest benefit from paint analysis and to avoid unnecessary
costs it is important to develop a precise brief for the investigations.
This process is best undertaken in conjunction with the analyst,
so the abilities and limitations of the process can be fully explored
and taken into account. For example, if it is an important component
of the project to assess whether the cornice is original to the
creation of the room, the paint investigations can be targeted
to provide a timely answer to this question.
will also require as much historical background information as
possible before commencing work. This will give him or her an
idea of the best areas to take samples from, as well as providing
the context within which the findings are placed. Most paint analysts
are trained architectural historians and capable of undertaking
such work, but in some instances it might prove more cost effective
to have such historical information prepared in advance.
18th century marbling at Hanbury Hall in Worcestershire: the
presence of an earlier trompe l'oeil scheme was indicated
by cross-section analysis of paint samples, and confirmed
by carefully scraping back the upper layers to reveal the
composition of the scheme.
historical research, the analyst will need to take small samples
from the building. These
may be removed before work starts on site but often further site
visits are made as the project progresses, possibly once demolition
or uncovering work has commenced. In this manner access can be
provided to previously inaccessible areas. It is important that
any access restrictions and scaffolding requirements are discussed
at an early stage so that the investigations can be properly planned.
Once the samples
have been set and examined microscopically, the process begins
of marrying up the information gleaned from analysis with the
information gleaned from the historical research.
product of a programme of paint analysis will usually be a small
archive of resin-set samples and a report tailored to the brief
outlining the conclusions drawn by the analyst. This report usually
includes a section describing the paint layers or 'stratigraphy'
of key paint samples, including the materials and methods employed.
Another section then presents the conclusions with an account
of the chronological sequence of individual decoration schemes,
and setting out what has been discovered about the architectural
development of the room and its decoration. It would also be expected
that any specific queries raised in the brief are answered in
this section. The explanation of the findings is normally assisted
by the inclusion of photomicrographs, a sample list, sample location
photographs and often tables charting the various schemes identified.
receipt of this report, it may be necessary to initiate a second
stage of investigation in which paint layers are scraped back
to uncover a specific decorative scheme, such as stencilling,
to determine its pattern, or to reveal a particular paint colour
so that the analyst can colour-match it. An understanding of the
materials employed will give a good idea of how the paint finish
may have aged, enabling the paint analyst to show the decorator
how to recreate the original colour, without being misled by the
current colour in its degraded state.
information contained within the report will help the conservation
team (the architect, surveyor, curator and others) to solve conservation
issues and guide them in choosing an appropriate model for presenting
the final results to the owner or the public. As the report should
also include a description of the materials and techniques employed,
it may also be of assistance in determining a suitable conservation
approach for the fabric. However, it is important to involve the
paint analyst in these curatorial and technical discussions, as
his or her understanding of the building's historical development
and decorative techniques may be critical to the decisions eventually
Royal Victoria Park bandstand, Bath (1880s) as found. Above right: the bandstand after its redecoration. The colour scheme, which probably
dates from the Edwardian period, was chosen because it was
the one about which most could be discovered from the paint
should be given to where resin-set samples should be stored, as
these may provide a convenient primary source of reference for
future research, and if the surface from which they came is ever
stripped, they will be the only primary source; unique, irreplaceable
and invaluable. Larger organisations, such as the National Trust,
may have their own repository but more often than not it is the
paint analyst who will keep them for future reference.
is always the risk that the analysis will reveal that substantial
paint stripping has been carried out in the past, limiting the
scope of the information gained, paint investigation is an exciting
and important tool in the conservator's and curator's armoury.
Based on sound analysis of the surviving paint layers (or archived
resin-set samples) and thorough historical research, a paint analysis
report should help them develop a clearer picture of how their
building or interior evolved, and should enable them to make more
informed decisions when considering its conservation and presentation.
article is reproduced from The Building Conservation Directory, 2006
OESTREICHER is an architectural historian and analyst of
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