The Benefit of Hindsight
Some Tips on Commissioning Paint Analysis
The following is an article based on a paper given at the English
Heritage Layers of Understanding conference that took place
in London on 28th April 2000.
Architectural paint research has progressed enormously
in the sixteen years that I have been involved in the field. It
is increasingly understood that properly conducted analysis can
reveal a great deal of information about a room's decoration, development
and use. However, there is still some confusion about how such work
should be commissioned and carried out.
The aim of this paper is to provide a number of
tips to the potential client in order that he may get the best out
of his project.
It should go without saying, that when one employs
a paint researcher, it is essential to ensure that he 1
is capable of carrying out the job. How does he intend to set about
it ? What projects has he worked on in the past ? What techniques
does he propose to use ?
The first thing to stress is that a paint scraper,
or "scrapist" (the word derives from "quack"),
will not be able to provide any meaningful information about the
sequence of paint layers applied to a surface. Pigment identification,
the dating of individual schemes, and the ability to identify (for
example) exactly which cornice elements were gilded, and at what
stage, are not possible by scraping through layers of paint.
2 A white-coated lab technician, on the other hand, may be
able to provide an elemental analysis of each of the components
within a paint layer, but will not necessarily understand the appearance
of a scheme, nor the intention behind its use.
Until the recent release of English Heritage's
Draft Guidelines on architectural paint research, it had been fourteen
years since Frank Welsh, the American paint researcher, published
his "Call for Standards" in a North American preservation
In his article, Mr Welsh listed the minimum requirements
of a paint analyst as being..."a:
1) Working knowledge and developed skills with
stereo and polarised light microscopy and microchemical testing
techniques, demonstrated through specific study and experience.
2) Comprehension of architectural building history
and technology, demonstrated through specific study and experience.
3) Knowledge of historic architectural-finishes'
manufacture and application technology, as demonstrated through
study, experience, teaching, lecturing, publishing, etc.
4) True understanding and perception of colour
and how pigments and paint colours are affected by ageing [sic].
5) Professional willingness and ability to evaluate
findings and/or techniques with others who are qualified in relation
to individual project/client requirements."
These criteria have not changed, although they
do need re-emphasising.
Experience of Researcher
A good paint researcher will probably have been
doing the job for ten years or more; will have made some form of
contribution to the field, and have carried out a hundred or so
projects. In other words, he will be somebody who knows exactly
what he is doing. The client should listen to the researcher, whose
aim will be to carry out the job as quickly, accurately and efficiently
Projects take many forms. If advice is wanted on
the way that colour was used in an interior of a particular period,
a report should not take too long to prepare. However, if an analysis
of the paint is required, it is essential that enough time to complete
the work is allowed. Whilst it is possible that an interim report
can be issued within a few weeks, a full, illustrated report - possibly
amounting to seventy or more pages - will take much longer to produce.
The size and complexity of the job will obviously have a direct
bearing on this.
Whilst understandable, a client should not try
to specify the number and location of samples to be taken. It is
possible that repairs have been carried out previously, and sufficient
samples need to be taken to avoid such anomalies. It is equally
possible that surface detailing, or polychromatic decoration, was
employed. It is far quicker for the researcher to take all the samples
that are needed at one time, than to make an unnecessary return
visit. A sketchy report will seldom justify the effort, and may
well raise many unanswered questions.
On the matter of return visits, occasionally the
researcher will need to go back to the site, in order to take confirmatory
samples. Time must be allowed for this eventuality. To be told as
I was recently, that a project had to be completed as follows, defies
In this case:
The contract, following the tendering operation,
was to be awarded on 4th February. Samples were to be removed by
18th February (some two weeks later), and the report was to be submitted
by 3rd March (i.e. within a month). Furthermore, access was limited
to six hours on Sundays and Mondays, Wednesdays and Thursdays. Accommodation
would be necessary, because of the distance from home, and the Tuesday
would be spent inactive as the site was closed. This was not just
for one room, but five areas of a building known to contain nineteenth
century polychromatic decoration.
As if to emphasise the ignorance of the project
managers, the colours identified had to conform to RAL numbers.4
Quite what would have happened if each of the colours did not match
the 180 or so colours in that range was not explained. This business
of specified paint colours will be discussed later.
As with any specialised, and little understood,
discipline, there is no shortage of cowboys. Certainly, there is
every reason for a potential client to be hesitant about accepting
the first quote for paint analysis. I was recently asked to look
at a building where, before my arrival, the information revealed
by a paint scrapist was found to be wanting. When asked to recommend
somebody who could take and examine cross sections my client had
been told that 600 samples would need to be taken from within the
room, and that the bill would be in the region of £30,000. My quote
was less than a tenth of that.
Clearly it is important to keep costs down to a
minimum, but to try and handicap the analysis by limiting the samples
to an unrealistic number is self-defeating, and no researcher worthy
of that name will comply with such a request. Analysis is not always
the answer, and the expense and the information that can be obtained
is neither warranted nor relevant in a number of instances. Provided
that the original paint is not removed, no damage should be caused
by overpainting, and the earlier layers can be left for another
An inexperienced researcher may offer to take a
few samples from a large number of rooms with the aim of helping
the client form an idea of the general treatment. This can backfire
if the client, or as happened to me, an English Heritage inspector,
then comes onto the scene and insists on knowing how each moulding
and element in twenty three rooms had been treated. Three years
later, I was still going backwards and forwards in order to answer
increasingly specific questions. In spite of being allowed to put
in a slightly larger bill for this extra work, it turned into another
pro bono job.
The paint researcher will want to have a clear
brief... why is the project being carried out, and with what aim
in mind ? Just to ask for "paint research" is not enough.
Is the first scheme applied to a surface considered
the most important, or perhaps that was just an interim scheme applied
before the full carbonation of the lime plaster ?5
Perhaps an analysis of the first scheme, with a summary of the later
"significant" ones would be more useful ? Schemes that
are slightly unusual or noteworthy in some way - perhaps painted
imitations of marble or woodgrain - might be included in this. Information
on the use of gilding, the presence of expensive pigments, or finishes
that one might not expect to find on such a surface might also prove
Bear in mind that if one wants to know about the
decoration applied during the occupancy of a notable individual,
a full analysis may be required in order to establish datum points
both before and after that period. The positive identification of
pigments and components within many of the paint layers will be
especially relevant in this sort of situation.
Inevitably, however, if a full-blown analysis is
required, it will not be cheap. The report following such work may
well go into great detail outlining the components and appearance
of each of thirty or so schemes applied to a surface, and may involve
the use of some bought-in services such as the use of scanning electron
Having said that, the mighty weight of detailed
scientific analysis is sometimes misused, and the results not altogether
relevant. When investigating house paint a thorough understanding
of the methods and materials of the early house-painter will often
enable a clear interpretation of the paint stratigraphy seen under
the microscope. The client should listen to the advice of the researcher
on the type of analysis appropriate to answering his brief.
A few years ago I was asked to look at a couple
of cross-sections in the laboratories of a major museum. The technicians
knew that the paint from a late 18th century room contained lead,
phosphorous and possibly carbon, but were unsure what this indicated.
They did not know whether it was unusual, nor what sort of colour
would have been produced. No one in that laboratory had any background
in architectural paint.
A few days later, following a lecture, I was asked
what methods I employed for medium analysis. I looked rather blankly
at my questioner, and said that beyond identifying whether a scheme
was in oil or water, there was seldom a need to go further. It was
clear that I had failed to convince him, but whether a house paint
was based on raw linseed oil, boiled linseed oil, walnut oil, or
poppy oil in most cases is not going to justify the expense
required to find out. The context will often supply the answer.6
If considered important it is possible for such work to be done.
There are some who, having learnt of the potential
of paint analysis, set out to employ it at every opportunity. This
is a mistake, and will often lead to frustration and a failure to
Exterior railings invariably display a sequence
of greys, greens, sometimes red-browns, and latterly black. To be
asked as I was, a number of years ago, for a full analysis of the
paints applied to a set of railings dating from the 1860s made little
sense. As a matter of course, I will usually indicate the presence
of any date-relevant pigment, such as titanium dioxide (which tends
to appear from the late 1920s onwards), and will certainly record
the sequence of colours. However, quite what was achieved by having
to report on the constituents of each of the schemes, including
the undercoats was lost on me, and, I suspect, the client.
The adoption of the "So What"
rule will generally prevent a meaningless paint report. The information
given should be presented so as to answer that rule. What do the
facts reported on tell us about the building or structure? Do they
answer the client's brief ? Is the information completely superfluous
? Above all, the researcher must not lose sight of the fact that
his report should be comprehensible, and not full of obscure technical
I well remember going to look at a small terrace
of derelict late-eighteenth century houses that were being renovated
as part of a housing project scheme. Having walked around the buildings,
I suggested that rather than employing paint analysis, the client
should consider painting the buildings in a manner that reflected
conventions of that period. However, I was persuaded to take samples
from remnants of damaged skirting boards, and from joinery that
had been removed, poorly labelled, and put into store. The plaster,
too, had been hacked off in several rooms and my report was spectacularly
unrevealing. Pretty well each paragraph would have failed the "So
Skills of the Researcher
I have tried to emphasise the importance of appointing
a paint researcher who knows his, or her, job. They will have experience
of many aspects of decoration, paint, and colour, and will know
how to combine theory with practice and be able to assist with the
preparation of the schedule of redecoration. But remember, just
because the researcher will have a passing acquaintance with science
does not mean that he will not know his Adam from his Yenn, nor
his Asprucci from his Botticelli.
As well as understanding modern colour theory,
the paint researcher will know of early notions of colour harmony;
the effect created by combining various pigments; the colours available
and popular in certain periods, and have a sound knowledge of early
texts on house painting and decoration. He will also have seen the
results of numerous redecoration projects. Furthermore he will be
able to advise on the correct type and finish of paint to be used.
To suggest that he is, almost by definition, somehow visually inept,
and lacking in aesthetic sensibility, is likely to be far off the
There is a common fallacy (and this is unlikely
to endear me to the two professions), and that is when it comes
to matters of decoration, architects and architectural historians
invariably know best. They may well be masters of their chosen fields,
but are unlikely to have made a deep study of architectural colour.
Sharing of Information
House curators are often so protective of their
charges that they are reluctant to pass on information that might
help with the paint research. There is occasionally a tendency to
regard the paint researcher as a member of one of the mechanical
trades. It is frequently the case that copies of building accounts
and other documentary information are not passed on, because it
is not considered relevant to the project. Furthermore, the researcher
is sometimes regarded as not the sort of person who might understand
such documents. Even on one of the largest restoration projects
carried out in the last ten years, a lot of persuasion was required
before I was allowed sight of the allegedly unimportant family papers.
Do consider that a paint researcher, in many instances,
can turn a seemingly bald entry in an account book into a colour;
into a medium (i.e. oil or water), and also a finish (i.e. flat
or glossy). The colour of the border boards in the Privy Garden,
at Hampton Court, for example, was identified by a knowledge of
the price of painters' work and materials in the 1700s. Analysis
of the paint was not possible as the original border boards had
long since perished.
Frequently I have been told that there is no information,
and almost as though it were an initiative exercise, have been left
to learn of the history of the house from the usual sources. After
one particular job, I received a letter from the curator thanking
me for "the absolutely brilliant" comments on the paint,
but then she went on to castigate me for not having referred to
her latest version of the guidebook. Had I been supplied with the
newest information on the house, the relevant chapter in my report
would have been up to date, and the interpretation of the cross
sections made somewhat easier.
The "Doubting Thomas"
Exceptionally, one will come across a curator who
refuses to believe what has been found, claiming that it counters
accepted historic practice, but citing no evidence. The only occasion
where this happened to me concerned a series of dark red-browns
being identified on doors and skirting boards of an early 18th century
London house. It was suggested by the curator that the sequence
of schemes with alternating varnish layers, were perhaps undercoats
based on red lead, and not the red and brown oxides that had been
identified by analysis, and illustrated by photomicrographs in the
report. A careful letter, citing numerous documentary and pictorial
examples to support the use of brown on doors and skirtings, was
enough to deal with that issue. However, one was left wondering
whether that historic house would not have been happier employing
an interior designer to devise "tasteful" schemes, if
that was what was really wanted.
Health and Safety Issues
There is no doubt that a well-trained paint researcher
will have wide-ranging skills, but a fearless, death-defying superman
he is not.
Perhaps one of the most frequent problems encountered
by the analyst is the failure of the client to provide safe, or
even adequate, access. Even I, who used to be a military parachutist
in a previous existence, find some of the ladders and scaffolds
offered to me scary in the extreme. Indeed, there have been times
when I have wondered if I would ever complete the sampling in one
It is unrealistic, indeed, can only lead to heavily-qualified
statements in the final report, to expect a whole ceiling to be
sampled from an immovable platform. If elaborately decorated it
is possible that fifty or more samples will need to be taken. Sometimes
too, one is asked to examine a ceiling forty or fifty feet high.
It is immensely helpful, and reduces much time-wasting, if one can
call on help to move the tower.
A researcher is only human and needs a few basic
facilities in order to function efficiently. Sites are often cold,
and a wise consultant will have learnt to bring adequate clothing,
and a sandwich or two in order to survive the day's sampling. However,
the provision of water and sanitation, allows one to concentrate
fully on the paint in a room, and prevents unnecessary anxiety,
and lengthy interruptions while the local geography is explored.
Light too, comes in handy, if one is to make an
effective examination. It really does help if the researcher is
warned beforehand to make special arrangements if there is no power
on site. However, in such an instance one must not be surprised
if the expenses part of the final bill is increased to reflect these
arrangements. Is it realistic for a London-based analyst to arrange
for scaffolding towers and lighting if the job is in Scotland ?
Surely the client, will have far better local knowledge of how to
arrange these things.
Paint researchers are a hardy lot, and have, and
will battle on against most impediments thrown in their way, but
there is perhaps one thing that is guaranteed to cause them to question
the seriousness of their client's intentions. This concerns a frequent
insistence that the nearest British Standard, or RAL, colour reference
is quoted for each of the colours encountered during analysis.
This almost amounts to the same as Henry Ford's
The customer can have any colour he wants so
long as it's black. 7
On many occasions the researcher submits his report,
and that is the end of his input. Often, years later, he may revisit
the site and see a most hideous misinterpretation, something that
could have been avoided by a continued, albeit small scale, involvement
with the project.
A paint colour should be indicated in the report
by a painted sample, and the relevant colorimetric information ought
to be included in order that paint can be reproduced exactly.
Spectrophotometry has consigned paint ranges with
only 57 varieties to the scrap heap, and now nearly every colour
can be reproduced with a degree of accuracy hitherto unknown.
Not only can a paint be produced that matches that
found on a site, but it is possible to ensure that each tin that
is applied matches the standard (or target) exactly. Can it make
sense, having established a decorative scheme by analysis, to mix
the paint in dustbins, and then to find out that not quite enough
has been mixed. Does no one ever think about future maintenance
implications ? Surely it is better to formulate the colour exactly,
so that any quantity can be bought on a future occasion with no
delay or unnecessary expense ?
For a happy, successful, result it is essential
that the client endeavours to work with the paint researcher and
not against him. Use him for everything that he can offer. Often
as a result of making the inevitable mistakes in his early years
he has a great deal of practical experience to draw on.
1.The use of the male pronoun is purely a literary device. The
author also acknowledges that most paint researchers are female.
2.It should be understood that a "scrape"
in this context is the action of scraping away overlying layers
of paint in order to see what lies below. An "exposure"
or "revelation" is the scraping away of superficial layers,
having established the stratigraphy by cross section beforehand.
This is done in order to provide further information about the earlier
The argument against scrapes has been well rehearsed.
See the following:
Morgan Phillips and Christopher Whitney, "The
Restoration of Original Paints at Otis House," Old Time
New England. Boston, Mass.: The Society for the Preservation
of New England Antiquities, vol LXII, no 1, (Summer 1971): 25-28.
Morgan Phillips, "Problems in the Restoration
and Preservation of Old House Paints," in Preservation and
Conservation, Principles and Practices. Washington, D.C.: The
Preservation Press, 1972: 273-285.
Ian C. Bristow, "Repainting Eighteenth-Century
Interiors," ASCHB Transactions vol vi 1982 (1981): 25-33.
Patrick Baty, "The Role of Paint Analysis
in the Historic Interior," The Journal of Architectural
Conservation (March 1995): 27-37.
Patrick Baty, "To Scrape or Not," Traditional
Paint News vol 1, no 2 (October 1996): 9-15.
No literature outlining their benefits is known,
though, incredibly, the practice is still very much alive in many
3.Association for Preservation Technology Bulletin,
vol xviii, no 4 (1986): 4-5.
4.A range of colours standardised by the Reichsausschuss
für Lieferbedingungen (RAL) [National Board of Supply Conditions].
This organisation was founded in Berlin, in 1925, to regulate and
set the standards for quality in industry.
5.Fresh lime plaster has a high pH, and can adversely
affect an oil paint that is applied directly on it. Traditionally
a surface was allowed to dry out, and the pH levels to drop, before
a scheme in oil paint was put on. A water-based soft distemper,
which allowed a certain passage of moisture vapour, was often applied
as an interim measure.
6.By context, price and location would often suggest
which oil was employed:
a) Interior colours would generally be made up
with raw linseed oil;
b) An early exterior paint is likely to have contained
boiled linseed oil;
c) Being paler, walnut oil appears to have been
widely used to obtain a white on large expanses;
d) Poppy oil seems to have been used infrequently.
It was the palest of the vegetable oils, and was rather expensive.
7.The Model T Ford Club, "Great Quotes by
and about Henry Ford and the Model T". [http://www.modelt.org/tquotes.html]