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Applied Decoration for Historic
Interiors Preserving Composition Ornament
Jonathan Thornton and William Adair, FAAR
Anyone who has ever walked through historic houses and large public
buildings, visited an art gallery, picked up a picture frame in an antique
shop, or even ridden on an old carousel has been close to composition
ornament, but has probably not known what it was or how it was made.
This is not surprising, since composition or "compo" was conceived as
a substitute for more laboriously produced ornamental plaster and carved
wood and stone, so was intended to fool the eye of the viewer (see Fig.
1). The confusion has been heightened over time by makers who claimed
to be the sole possessors of secret recipes and by the variety of names
and misnomers associated with the material, including plaster,
French stucco, and Swedish putty, to name a few.
Many natural or man-made materials can be made soft or "plastic" by
the application of heat and are called "thermoplastics." Composition is
a thermoplastic material used to create sculptural relief. It is soft
and pliable when pressed into molds; becomes firm and flexible as it cools;
and is hard and rigid when fully dry. Typically formulated with chalk,
resins, glue, and linseed oil, this combination of materials gives compo
its familiar light-to-dark brown color. It is the only one of the so-called
thermoplastic materials to be used extensively in architectural decoration
because of its low cost.
Generally adhered to wood, historic composition ornament is most often
found decorating flat surfaces such as interior cornice and chair rail
moldings, door and window surrounds, mantelpieces, wainscot paneling,
and staircases-indeed, anywhere that building designers and owners wanted
to delight and impress the visitor, but stay within a budget. While composition
was cheaper than carved ornament, it was still meticulously hand made
and applied; thus, it was more often used in "high style" interiors. But
the types of structures historically decorated with composition ornament
were more democratic, encompassing residential, commercial, and institutional
buildings, and even including specialty applications such as the social
saloon of a steamship (see Fig. 2).
With proper understanding of the material, historic composition ornament
may be successfully cleaned, repaired, or replaced in sections. Unfortunately,
because composition is often misidentified as plaster, stucco, or carved
wood, the use of inappropriate methods for removing paint is a major cause
of its loss (see Fig. 3). The purpose of this Brief is to to assist historic
property owners, managers, architects, craftsmen, and preservationists
in identifying existing composition ornament, determining the extent of
repair and replacement needed and, finally, selecting the most sensitive,
non-destructive method of treating it.
De-Mystifying the Mix
While various types of moldable composition date to the Italian Renaissance,
architectural use of composition did not begin to flourish until the last
quarter of the 18th century. During this period, many composition ornament
makers in Europe and America supplied the public with complex sculptural
decoration. Also, the overly complicated and often intentionally mysterious
earlier recipes were now reported to be comprised of a few basic ingredients:
animal glue, oil (usually linseed), a hard resin (pine rosin or pitch
was cheapest), and a bulking or filling material, generally powdered chalk
or whiting (see also Sidebar, Compo: The Basic Ingredients).
Compo: The Basic Ingredients (clockwise from front center)
(sidebar and photo)
Chalk: Chalk is whiting in solid form. It is a type of
white, soft limestone.
Glue: Before the invention of synthetic adhesives, glue
meant animal or hide glue. This was made by boiling animal skins to extract
a protein-collagen-in water, then condensing and drying the collagen until
it was in solid form. A variety of types and grades were, and are still,
available. Two are shown here.
Linseed oil: This is a yellowish drying oil obtained from
flaxseed that is used in paint, varnish, printing ink, and linoleum; it
is a key ingredient in composition ornament.
Resin: Resins are organic materials present in wood and
exuded from various trees and shrubs. In unrefined form, they often consist
of a mixture of solid natural polymers, oils, and volatile aromatic substances.
Compo mixes have been the subject of a good deal of variation and there
has never been a set recipe, but the ornament manufacturers of the later
18th and early 19th centuries understood in general terms what their material
was and what it could do (see Fig. 4). The advantages of the material
were described by a prominent American maker, Robert Wellford, in his
advertising broadside of 1801:
"A cheap substitute for wood carving has long been desirable for some
situations, particularly enriched mouldings, etc., and various were the
attempts to answer the purpose, the last and most successful is usually
termed Composition Ornaments. It is a cement of solid and tenacious materials,
which when properly incorporated and pressed into moulds, receives a fine
relievo; in drying it becomes hard as stone, strong, and durable, so as
to answer most effectually the general purpose of Wood Carving, and not
so liable to chip. This discovery was rudely conducted for some time,
owing to Carvers declining every connection with it, till, from its low
price, it encroached so much upon their employment, that several embarked
in this work, and by their superior talents, greatly improved it."
In brief, compo is perhaps best understood as an early thermoplastic
that allowed the rapid reproduction of complicated detail for popular
use.
Making Composition
Ornament: A Process Unchanged
Since the craft has essentially remained the same over time, a description
of its historic manufacture is also applicable today (see Fig. 5).
In one container, chunks of amber colored pine rosin or the cheaper
black pitch were heated in linseed oil until they melted together and
combined completely. In another container (often a double-boiler), previously
soaked chunks of animal glue derived from skins and hides were cooked
and blended into a uniformly thick solution. The two liquid components
were then stirred together. This "batter" was made into a pliable "dough"
in a way familiar to any baker. It was poured into a cratered pile of
whiting and first mixed with a spatula until it was thick enough to be
kneaded by hand. Vigorous folding and kneading in of more whiting was
done until the composition had a consistency like modeling clay and was
completely uniform.
To mold a decoration, the compo was first warmed in a steamer, and the
mold prepared with a thin coating of oil and a dusting with talcum powder.
A piece was then kneaded and folded to produce a smooth and wrinkle-free
surface on one side. The good side was placed down over the rigid mold,
and pressed in loosely with the fingers, leaving excess above the surface
of the mold. A damp board was placed over this and the "sandwich" placed
in a screw press and squeezed so as to force the compo into the finest
detail. It was then removed from the press and turned over so that the
mold could be lifted straight up, leaving the compo stuck to the board.
Upon cooling to room temperature, the compo gelled, becoming tough and
rubbery (the gelling property is due to the glue component which is chemically
identical to edible gelatin). At this stage, it was sliced off the board
with a thin-bladed knife. The remaining mass of composition still adhered
to the board could also be sliced off and reused.
Composition ornament was often fixed to an already prepared wooden substrate
at the factory while it was still fresh and flexible, but could be dried
and shipped to the final user, who would make it flexible again by steaming
on a cloth stretched over a container of boiling water. Instructions for
doing this, as well as suitable brads for "fixing," were supplied by some
manufacturers. Because of the glue component, steaming the backs of ornaments
would make them soft and sticky enough to self-bond without additional
glue. Soft ornaments were softened nailed through or pressed down on top
of previously driven headless brads (also called sprigs). Strings and
wires were often included in the mass during pressing to serve as internal
armatures and reinforcements. These measures preserved the integrity of
the ornaments even if they cracked.
Originally meant to copy other materials such as wood, plaster, and
stone, composition had its own unique properties and advantages that were
soon exploited in both technical and artistic terms. It has distinct characteristics
in each of its three states: pliable, rubbery, and hard. When warm and
pliable, it can be modeled by a skilled worker and it is capable of receiving
the finest detail when squeezed into a mold. After it has chilled to room
temperature and is gelled, it is rubbery, flexible, and tough. The detail
is essentially set and cannot be easily damaged as the ornaments are manipulated
(see Fig. 6).
Gelled composition ornaments can be easily bent over curved surfaces
without cracking, and unlike a rigid cast material such as plaster, they
can be stretched or compressed somewhat to fit a design without damaging
the detail. An egg and dart motif, for example, could be made to come
out evenly at the corners without making a partial egg or dart. The sculptural
vocabulary from the maker's mold collection could be re-arranged at will
into larger decorative schemes. In fact, any smaller component of a decoration
from a single mold could be sliced free and inserted into any location.
Composition could be carved to heighten detail, correct defects, or
undercut ornaments-that were, of necessity, straight-sided-so that they
would release from the rigid molds. This could
be done in the gelled state or, with more difficulty, after it had finally
hardened to stone-like solidity.
Finally, when completely hard, it could be given a polished marble shine
with nothing but a damp cloth. It could be stained, coated with any sort
of paint, varnish, or oil gilded without any further preparation (see
Fig. 7).
Molds and the Creation
of Patterns
A technical discussion of composition is not complete without an examination
of the molds used to create the ornament. These were the ornament maker's
largest investment in time and expense, and were the key to the craft
(see Fig. 8).
Composition molds were always made of rigid materials that would withstand
the considerable pressure used in pressing the ornaments. All of these
materials and methods have been used in sculptural crafts since the Renaissance.
The comparative listing that follows helps explain their advantages
and disadvantages.
Wood was carved in reverse to create a negative matrix. This
was highly skilled work often performed by a specialist carver, and required
a large initial investment in time, but wooden molds would essentially
last indefinitely if properly maintained. A further design advantage of
reverse carving is that fine incised lines will show up as fine raised
lines in the final ornament. (Fine raised lines are notoriously difficult
to carve or model in relief.) Molds carved from dense and close-grained
fruit woods such as apple and pear seem to have been common in the 18th
century. In the 19th century, the most intricate molds were carved in
boxwood, often encased or framed by larger and cheaper pieces of timber
for ease of handling and to prevent splitting.
Metal alloys such as brass, bronze, and pewter made excellent
molds capable of yielding the highest level of detail and were virtually
indestructible in use. They were expensive due to the intrinsic value
of the metal and because their production involved a variety of complex
and skilled steps performed by modelers, pattern makers, and founders.
Few historic metal molds have survived, possibly as a result of wartime
scrap drives.
Sulfur melts into a clear fluid at about 115 C and could be poured
over a positive clay model or another compo ornament. A sulfur mold resembles
hard plastic, but is more fragile. Even when framed in wood and reinforced
with iron fillings, as was common practice, it was especially vulnerable
to breakage. A figural design, such as a frieze of The Three Graces,
was much easier to model in relief than to carve in reverse, and sulfur
was one of the few materials that could be used to make a hard mold from
a clay model.
Composition itself could be squeezed over a hard relief pattern
(such as another manufacturer's ornament) to make a mold. Composition
shrinks as it hardens and so the mold was always smaller than the original.
It is also fairly brittle when hard and, like sulfur molds, would tend
to crack in the press. Composition "squeeze molds" were ideal for pirating
another maker's patterns!
Pitch molds became popular during the late 19th and early 20th
centuries. A warm and soft mixture composed primarily of pine pitch was
poured into a recess in a wood block or frame. It was then turned over
and squeezed down onto an oiled wooden pattern. Pitch molds might crack
with age or in the press, but as long as the carved pattern was retained,
they could be easily re-made.
Historical Survey
Early History and Renaissance. Press-molded decoration
has been used with various soft plastic materials for centuries. For example,
it is known that medieval sculptors press-molded organic mixtures to decorate
painted sculptures. But because mixtures based on organic binders such
as glue, oil, resins, and waxes are prone to various sorts of degradation,
actual survivors are rare.
The direct ancestors of the composition craft are most likely found
in the Italian Renaissance; however, composition mixtures were not extensively
used for architectural decoration during this period, probably due to
building traditions as well as relative expense. It is worth nothing that
this was an age of experimentation with materials and rediscovery of Greek
and Roman designs. Press molded mixtures called pastiglias were
used to decorate wooden boxes and picture frames as early as the 14th
century (see Fig. 9). Moldable compositions were discussed by various
Renaissance writers. The recipes are extremely varied and include, among
their more common and understandable ingredients, gypsum, lead carbonate,
wood and marble dust, eggs, pigments, sheep's wool, and various oils and
resins.
The 18th Century. The first flowering of architectural
composition in America took place at the end of the 18th century when
ornaments were both imported from England and produced by makers in every
major eastern city. All of the conditions were right: molding technologies
were well established (architectural papier mache, which, like
composition, was produced in molds, had gained widespread acceptance during
the middle decades of the century). The raw materials were produced or
imported in volume, so the cost of the composition ingredients came down
as the cost and availability of highly skilled labor went up. Economic
and social conditions favored centralized "manufactories" in the production
of various arts and crafts.
Design trends also fed into a favorable reception for composition. A
more faithful reinterpretation of Greek and Roman design eventually termed
"Neoclassical" had taken hold in Europe, championed in England by the
architect, Robert Adam, after his return from study in Italy in 1758 (see
Fig. 10). Although Adam played no direct role in the "invention" of composition
ornament, as has sometimes been said, he patronized English craftsmen
who were making it and was generally receptive to new and innovative materials.
One early maker, sometimes cited as the "inventor" of composition by his
contemporaries, was John Jaques. His name appears in London advertising
by 1785, but he was probably in business before then (see Fig. 11).
As a result of Adam's influence, designers of applied ornament in both
Europe and America began to take advantage of a molding process that was
ideally suited to producing the detailed, but repetitive, motifs of classical
decoration-acanthus leaf, egg and dart, festoons, swags, and paterae-as
well as classical themes depicting Greek and Roman gods and goddesses
(see Fig. 12). And as the Neoclassical style became more popular, composition
ornament makers increased in number.
The 19th Century. During the early decades of the nineteenth
century, Neoclassical-encompassed in America by the terms Federal, Empire,
and Greek Revival-was in the ascendancy. Composition makers continued
to increase and also to find new uses for their material. Composition
picture and mirror frames became common and some makers advertised the
suitability of composition ornaments for casting iron firebacks and stoves.
Composition ornament was explicitly advertised for exterior use as well,
although very little has survived. The interiors of houses and public
buildings in every prosperous American city were decorated with composition
(see Fig. 13).
When the classically derived Federal and Empire styles gave way to the
various revival styles-Rococo, Gothic, Renaissance, and Italianate-composition
makers simply made new molds to accommodate them. (Although Rococo and
Renaissance styles were not common for architecture in America, they were
common for furnishings and interior decoration and, in consequence, for
composition ornament.)
Along with a proliferation of styles in the mid-to-late decades of the
century, there was a parallel growth in the number of moldable and castable
materials that shared some features of the composition craft, such as
carton pierre, gutta percha, fibrous plaster, shellac
compositions and, eventually, celluloid and hard rubber.
Composition continued to be the preferred material for detailed decoration
on wood where the size of the ornament did not make its cost prohibitive.
The publication of practical books by and for craftsmen, beginning in
the 19th century, disseminated recipes and procedures to a broad audience
and de-mystified the craft. Period composition ornaments called "imitation
wood carvings" were widely advertised in manufacturers' catalogs (see
Fig. 14). Balls of prepared compo became available from some art supply
shops in large cities for use by small volume craftsmen.
During the later years of the century, the Arts and Crafts Movement-as
preached by William Morris and his associates and followers-became increasingly
important in design and philosophy. Morris stressed honesty to the material
in design, exalted spirituality of hand work and rejected manufacturing,
mass production and the distinction between "high" art and craft. These
trends were to affect both technology and design in the 20th century.
Composition ornament would have been anathema to Morris and his elite
clients; most composition production during the last years of the century
is best described as Victorian Eclectic.
The 20th Century. The Arts and Crafts and related styles,
such as the more decorative Art Nouveau, were well rooted in America by
the beginning of the century (see Fig. 15). Pitch molds made from relief-carved
patterns had become common in America. The carving tool marks could be
accentuated in these patterns in keeping with current vogue. Open-grained
woods, such as mahogany, were often chosen so that the finished composition
ornaments would have a wood-like grain that showed through stains and
varnishes (see Fig. 16). A uniquely 20th century application of composition
ornament was in the lavishly decorated movie palaces of the Depression
era (see Fig. 17).
As interest in architectural embellishments declined, particularly as
a result of the austere post-World War II styles, so did the composition
trade. Many old firms went out of business and their molds were dispersed
or destroyed. The few that remained concentrated on restoration projects
or were sustained by diversification into other materials. By the 1950s
and 60s, composition as a material and craft had been all but forgotten.
An upsurge in hand craft production that started in the late 60s and
has continued to the present-as well as increasing interest in historic
preservation-has led to the renewed study of old methods and materials,
including composition. The few manufacturers that remain have seen a large
increase in their business, and an increasing number of people recognize
composition as a unique ornamental material and want to conserve, restore,
or create it (see Fig. 18).
Compo Deterioration and Damage
To some degree, the longevity of historic composition ornament is related
to the ratio of ingredients in the original mix and to the skill of the
craftsman in applying it. But it is far more dependent upon interior climatic
conditions and the long-term effects of heat and dampness on both the
compo and the wood substrate.
Variables in mixing and application. Dried compo is inherently
hard and somewhat brittle; its increasing brittleness over time is primarily
due to the oxidation and hardening of the linseed oil component. The drying
oil, in turn, contributes to age cracking. Thus, during initial manufacture,
if the oil content was low and the dry filler content (chalk) high, shrinking
and cracking over time is less likely to occur. Originally, the compo
was probably attached using small, headless brads (1/4") that penetrated
the hardening compo as well as the wood substrate. They were used to keep
the compo from shifting or warping after it was set in place. If an insufficient
number of brads was used by the craftsman during the application process,
the compo simply falls off as cracks develop.
Interior environmental conditions. Compo was conceived
as a durable substitute for hand-carved wood or marble and decorative
plaster; its potential for structural failure is generally due to substrate
failure rather than to the compo mix itself. Theoretically, composition
will move with atmospheric changes due to the moisture-sensitive glue
component. Its breakdown typically occurs when the wood base expands and
contracts at different rates than the compo during extreme temperature
and humidity fluctuations. Especially when it is close to a source of
heat, such as directly over a fireplace, compo develops fissures or shrinkage
cracks. Contemporary heating systems in old buildings also contribute
to the drying and cracking syndrome.
Planning for Treatment
Simple stabilization and repairs to existing ornamentation can most
likely proceed based solely on an analysis of existing conditions (see
paragraphs on Surface Cracking and Delamination,
below).
Historical research. For more complex work, a building
owner, curator, or conservator should research the history of the building
to find out when it was originally designed and constructed; who lived
in it at various times; how the building was used; and which features
were original and which were added later or removed (see Fig. 19). Some
of this information may be found in the National Register of Historic
Places.
Questions about the building's interior spaces and their decorative
detailing also need to be asked, particularly when portions of the ornamentation
will be replaced. Have the interior spaces evolved with successive occupancies
or uses? In addition to compo, were other decorative materials used and
are there differences in patterns that help date the work? For example,
plaster and compo may have been used in the same room, but applied at
different times. Receipts from workmen's bills may often be used to establish
the dates of decorative detailing.
The historical research dealing with the original construction of the
building and its use over time should, in turn, be linked to the scope
of work that will take place.
Stabilization, conservation, and repair are maximized within the treatment,
Preservation. Generally speaking, restoring decorative ornament to a specific
earlier period is not recommended unless its historical significance outweighs
the potential loss of extant ornament that characterizes other historical
periods. But if a significant interior is missing original features and
physical and documentary evidence are conclusive, replication may be appropriate
in order to interpret a particular time.
Existing conditions analysis. After historical research
is conducted, but before starting work, an analysis of the surface and
substrate should be undertaken. These are some of the issues a conservator
considers. First, if a surface is painted, the ornamentation material
needs to be identified. Is it wood, plaster, composition ornament, or
some other type of applied ornamental material? Usually, some of the ornamentation
is chipped or broken. Close examination of the exposed material is the
first step. If it is white through the entire thickness of the ornament,
then it could be plaster or stucco; if it is a darker brown material,
it is more likely to be composition.
After having identified the presence of composition ornament, its overall
condition can be evaluated. Layers of paint may obscure fine detailing
as well as deterioration problems. Degrees of damage and deterioration
should be recorded. These are typical questions that need to be answered.
Is the surface merely "crazed", requiring no action or limited repair,
or are the cracks severe enough to require replacement? Are pieces missing?
Are the attachment brads rusted or missing? The condition of the substrate
is also important. Is the wood surface intact, or is it in need of repair?
After answering key questions, the conservator will make random tests
to differentiate original compo from later repairs, some of which may
well have been done with plaster, rather than compo (see Fig. 20).
Deciding how to proceed depends upon the overall interpretive goals
of treatment. For example, is the interior being restored to an earlier
time? In this case, later repairs may be removed and the original appearance
replicated. Or is the interior being preserved with limited replacement
of lost or damaged historic materials? Not all conditions are foreseeable
in conservation work and contingencies must be incorporated into the treatment
plan to be considered realistic. As the project progresses, the conservator
generally determines the work that needs to be done, and the order in
which it should be undertaken.
Treating the Problem with Care
The scope of work is generally based on several factors, including the
historical significance of the building's interior, the degree of damage
or deterioration of the compo, and the overall interpretive goals of project
work. Several examples of repair and replacement follow in order to suggest
a typical scope of work within preservation and restoration projects.
Treatments are listed in hierarchical order, from the least intervention
to the greatest.
Paint removal. Interior ornament is usually painted many
times over during its lifetime and, as a result, the sharp surface detail
of the original pattern is obscured. Before attempting to remove paint,
it is always advisable to obtain professional advice on the ornamental
material to be cleaned as well as the nature of the coatings that are
covering it. And whatever the project work goal, at least one sample of
intact, well-adhered paint layers on a feature should be preserved for
future historical research.
Based on the purpose of treatment, these are some of the questions a
conservator routinely asks. How many layers of paint are there? Is it
important to trace one layer to a particular occupancy of the building?
If so, the stratigraphy (or layering scheme) will be determined prior
to paint removal. After the correct layer is identified, the color can
be matched. Or, is the building being rehabilitated? If this is the case,
period-typical paint colors may be appropriate.
For purposes of this Brief and the guidance paragraphs that follow,
it is assumed that all layers of paint are being removed in order to reveal
the fine detailing of the composition ornament (see Fig. 21).
The next step is to consider various methods of removing paint from
the ornament without damaging it, or without being exposed to dangerous
substances in the strippers or in the old paint itself! It should be noted
from the standpoint of health and safety that most Federal and Empire
period compo was meant to imitate marble; thus, the highly toxic white-lead
paint was by far the most common original coating.
Caustic strippers based on lye should be avoided for two reasons.
First, they will damage and dissolve compo both because they "chew up"
the protein structure of the glue and, second, because they are water-based
and compo remains soluble in water (see also Fig. 3). If a stripper will
damage the protein of your hands, it will do the same to compo!
A conservator will more often use organic solvents, such as methylene
chloride, in conjunction with small implements such as a dental tool or
toothbrush. (A small area is always tested first to establish the safety
and effectiveness of any technique. Improper use of stripping tools can
damage intricate surfaces beyond repair.) A solvent is applied according
to manufacturer's recommendations, permitted to soak into and soften the
paint, then re-applied as necessary, as the conservator gently removes
paint from the intricate carved surfaces (see Fig. 22).
It should be emphasized that any amount of exposure to toxic chemicals
without proper precautions can cause severe health problems. A hooded,
air-fed, personal unit is desirable when using methylene chloride-based
strippers if fume hoods or paint spray booths that exhaust effectively
to the outside are not available. Organic vapor masks may not be as effective
in protecting against methylene chloride exposure because the filters
quickly become exhausted; however, a vapor mask with properly rated organic
solvent cartridges can provide an acceptable level of safety when cartridges
are regularly changed (see Fig. 23).
Some conservators have had excellent results heat-stripping excess paint
layers using heat guns and dental tools. This is highly skilled
work and its success depends upon the composition ornament being much
older than the paint layers that lie on top, but has the capability of
working as well or better than chemical methods in the hands of an expert.
Precautions must be taken against lead fumes where removal of lead paint
is involved.
Cleaning mixtures based on enzymes are also used by conservators.
This is an effective method because enzyme mixtures can be formulated
for very specific purposes (i.e., to dissolve only oil-based paints from
protein-glue based compo). They dissolve paint without affecting the wood
substrate. But, on the other hand, work can be very slow and the expense
would only seem justified on small and rare or important museum objects.
Enzymatic cleaners are dependent on a high level of skill, technical knowledge
and professional training, but they are earning a solid place in the repertoire
of professional conservators.
Increased concern about the environment may well render the toxic methylene
chloride strippers obsolete in the near future. Manufacturers have already
produced "safer" strippers based on dimethyl esters, and further
research will probably yield other alternatives to chlorinated solvents.
Slower acting solvent-type strippers may well be safer to the underlying
composition ornament, but additional research and use are needed before
making definitive
statements.
In summary, most damage to compo occurs during the removal of layers
of paint; this is a critical process and should not be attempted without
consulting a conservator and should not be undertaken by painting contractors
unless they are highly skilled and have had extensive experience in this
very delicate procedure.
Proper disposal of residual chemicals and debris must be undertaken
to avoid contaminating the environment with solvents and lead, and such
disposal is, in fact, now required by federal, state, and local ordinances.
The company responsible for removing chemical waste should be licensed
to dispose of it, otherwise the property owner may be held accountable
if disposal laws are violated.
Refinishing compo ornament usually follows stripping. According to historic
evidence uncovered and depending on the existing and desired appearance
of the room, compo can be stained, painted, gilded, marbleized, or glazed.
Paint types may include distemper, alkyd oil, or latex. A thin coating
is recommended so the intricate surface detail is not clogged.
Surface cracking. Surface cracking indicates age and,
thus, the history of the ornamentation itself (see Fig. 24). It does not
necessarily mean that cracks have to be fixed. But if cracking interferes
with the overall design pattern, then the conservator may elect to fill
the cracks with suitable fill material. For example, "light weight" spackles
bulked with microballoons are excellent because they are soft and compressible
and will accommodate changes in the size of cracks due to moisture fluctuation.
After stabilization, the surface is finished to match the existing area.
Delamination. Delamination or separation of the compo
from the wood substrate is the simplest repair problem to remedy. The
conservator begins by testing cracked areas with slight finger pressure
to determine which parts of the design need consolidation. Compo sections
that have separated from the substrate, but are otherwise intact, can
be glued back in place using emulsion type adhesives such as "white" glues
or a clear, solvent-release adhesive (see Fig. 25). For vertical surfaces,
the glue is painted onto the back of the delaminated compo as well as
the wood base and, when slightly tacky, re-attached, and held with clamps
until dry.
Professional conservators often formulate their own adhesives based
on stable synthetic polymers (plastics) dissolved in solvent that will
be more reversible, should the need arise, and also offer better long-term
stability than many commercial adhesives.
Repairs to broken or damaged compo. When some original
compo has been lost, additional work is required to make a repair. One
particularly easy and inexpensive method of repairing broken ornamentation
is to use non-hardening clay ("plastilina") or polymer-based modeling
materials as an impression material to make a mold. After a mold is made
from existing ornament, missing or deteriorated portions of the historic
design can be duplicated with a durable gypsum plaster (see Fig. 26).
Especially in cases where economic considerations dictate procedure, use
of this substitute material may be helpful because it is cheaper. Alternatively,
an existing studio mold may sometimes be used to make small replacement
pieces in a repair project (see Fig. 27).
In another scenario, a repetitive design on a mantelpiece may be damaged
or portions missing. Especially if the compo design is complex and several
portions of ornament need to be replaced, rigid polymer molds with traditional
compo are recommended for the repair work. The mold is created using a
section of the original ornament as a model. After replacement pieces
are fabricated, they are attached using brads, or finish nails (see Fig.
28). The pointed end of the nail is clipped blunt with snips to avoid
possible splitting of the wood substrate. The nail is first hammered into
the surface, then countersunk, and the resulting hole filled with gesso
putty or additional compo.
Finally, a ready-made replacement piece can be ordered from the catalog
of a compo manufacturer, but it is unlikely to be a perfect match to an
extant historic decoration.
Replacement of missing compo ornamentation. Once-attractive
compo may become damaged to such a degree that the remaining fragments
are removed by an owner and the entire surface painted over. Thus, if
there is some existing composition ornament in a room, such as an overdoor
or chair railing, the conservator would most likely look for evidence
of other ornament that is now missing.
For example, a mantel may appear as a flat, unornamented surface to
the untrained eye, but after many layers of paint are removed by the conservator,
shadow images are revealed (see Fig. 29). These images or "ghost marks"
are left by the hide glue component of the original mix. Although the
glue is water soluble, it will not be completely removed by an organic
stripper such as methylene chloride. (But if earlier inappropriate paint
removal methods were used, such as water-based strippers, caustic strippers,
or mechanical sanding, ghost marks from the glue would be destroyed.)
When the paint stripper dries, a ghost mark left by composition ornament
appears slightly darker than the surrounding area where no compo had been
attached. In addition, small, square-headed, º" brads used to reinforce
the original compo may be embedded in the wood.
In summary, detailed physical evidence, as well as written and pictorial
documentation, can provide a valid framework for replacement at a particular
site. With careful detective work, missing historic ornamentation may
be successfully identified and replaced with matching ornament (see Fig.
30; see also Fig. 19).
Restoration of a "period" interior. When ornamentation
is extensively deteriorated and missing, owners often want to re-create
the historic appearance through restoration. Physical evidence and other
documentation may be used as a basis for the restoration; it should be
remembered, however, that as the amount of surviving material diminishes,
the greater the chance for inaccuracy when attempting to depict the historic
appearance. Choosing restoration as a treatment thus requires exacting
documentation prior to work and meticulous attention to detail in the
work itself.
Conclusion
Despite its popularity and widespread use as a decorative material,
the history of composition ornament has yet to be thoroughly studied.
Individual craftsmen have acquired fragmentary knowledge about some designs
and historic methods; historians and students of interior decorative design
have accumulated knowledge about patterns, artisans, and methods of manufacture
and distribution; and curators of historic collections that include compo
are knowledgeable about the objects under their care. The combined knowledge
of these individuals, together with examples and images of compo ornament
from a variety of sources, needs to be synthesized to address the complex
issues involving compo repair and preservation. The future of the study
of composition ornament, as well as many other facets of architectural,
decorative, and fine art history, lies in this sort of cooperative effort.
Cover photograph: The process of making composition ornament has
changed little over the years. In the J.P. Weaver Company, located in
Glendale, California, freshly made compo is being kneaded prior to pressing
it in a mold.
Further Reading
Adair, William. "An Investigation of Composition Ornamentation." The
Interiors Handbook for Historic Buildings II. Washington, D.C.: Historic
Preservation Education Foundation, 1993, Chapter 4, pp. 1-7.
Adair, William. The Frame in America, 1700-1900: A Survey of Fabrication,
Techniques and Styles. Washington, D.C.: The American Institute of
Architects Foundation, 1983.
Budden, Sophie (ed.). Gilding and Surface Decoration. London:
United Kingdom Institute for Conservation, 1991. See: Judith Wetherall,
"History and Techniques of Composition," pp. 26-29; Jonathan Thornton,
"Minding the Gap: Filling Losses in Gilded and Decorated Surfaces," pp.
12-17.
Cotton, J. Randall. "Composition Ornament." Old-House Journal.
Vol. XXI, No. 1 (January/February 1993), pp. 28-33.
Green, Malcolm. "Conservation and Restoration of Gilded Antiques." The
Conservator, 3. United Kingdom for Conservation, 1979.
Hasluck, Paul N. (ed.). Cassell's Cyclopedia of Mechanics, 8
vols. London: Cassell and Co., 1904, Chapter 4, p. 164.
_______________. Mounting and Framing Pictures. London: Cassell
and Co., 1899.
Kunou, C.A. Manual of Gilding and Compo Work. Los Angeles, California:
The Bruce Publishing Co., 1928. Request reprint information from the International
Institute for Frame Study, 2126 "O" Street, NW, Washington, D.C. 20037.
Loeffler, R.F. Step by Step Compo and Mold Making. Oroville,
California: Loeffler-Valac Industries, 1992.
Millar, William. Plastering Plain & Decorative: A Practical Treatise
on the Art & Craft ofPlastering and Modelling. London: B. T. Batsford.
New York: John Lane, 1899.
Scott-Mitchell, Frederick. Practical Gilding. London: The Trade
Papers Publishing Company, 1905.
The Gilder's Manual. New York: Excelsior Publishing House, 1876.
Reprinted by the Society of Gilders, Washington, D.C., 1990.
The Secretary of the Interior Standards for the Treatment of Historic
Properties. Washington, D.C.: U.S. Department of the Interior, National
Park Service, Preservation Assistance Division. Washington, D.C., 1992.
Thornton, Jonathan. "Compo: The History and Technology of `Plastic'
Compositions." Preprints of papers presented at the 13th annual
meeting, Washington, D.C. American Institute for Conservation, 1985.
Organizations
For information on conservators, contact the following organizations:
Association for Preservation Technology
904 Princess Anne St.
Fredericksburg, VA 22404
National Institute for the Conservationof Cultural Property
3299 K St., NW, Ste. 403
Washington, D.C. 20007
American Institute for the Conservation of Historic &
Artistic Works
1400 16th St.
Washington, D.C. 20036
Acknowledgements
Kay Weeks, project director for this cooperatively produced Brief,
is an art historian who serves as technical writer-editor in the Preservation
Assistance Division. Jonathan Thornton authored the historical
overview portion of the Brief and William Adair, FAAR, the planning
and treatment portion. The editor and authors wish to extend their gratitude
to those people who reviewed and commented on the Preservation Brief in
draft form and those who provided illustrative materials. First, National
Park Service staff reviewers included H. Ward Jandl, Blaine Cliver, Anne
Grimmer, Chuck Fisher, Tim Buehner, Emogene Bevitt, Tom Jester, Michael
Auer, and Paul Alley. Specialists in the field included Andrew Ladygo,
David Flaharty, Phil Gottfredson, Mark Reinberger, and Lenna Tyler Kast.
Photographs were generously donated for the Brief by Philip L. Molten,
Elizabeth Brick, Robert J. Rucinski, Lenna Tyler Kast, Bryan Blundell,
Thomas Brunk, Lonnie J. Hovey, AIA, Roland White, Irving Haynes &
Associates, Philadelphia Museum of Art, Cleveland Museum of Art, the Freer
Gallery of Art, Winterthur Library, Decorators Supply Corporation, and
Rapid Photography, Inc.
Washington, D.C. May, 1994
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