Gilding a Naderman Harp
In December 2008, an 18th century harp built by harp maker Jean-Henri
Naderman was brought to my studio for gold restoration.
had come from its long-time home, a convent, and was purchased at an auction
in Freeport, Illinois by Peter Reis of Harps Unlimited, who sent it to Pat
Dougal’s PRD Harp Services in Joliet, Illinois, as it was badly in need of a
transformation. It was an honor for me to participate in the restoration of
this splendid harp. This was my first introduction to a Naderman. I learned
Naderman was born in 1735 in Frebourg, Switzerland. In 1778, he was
appointed harp maker to Marie Antoinette, Queen of France. Marie
Antoinette’s love of music and playing the harp made it popular and
fashionable. By 1784, there were as many as fifty-eight harp teachers in
The Naderman harp was a beauty in ebony and
gold with its richly carved gilded ornament, though the gold’s sealed finish
had dulled and darkened from many years of soiling and age.
The neck and column were one continuous piece
crowned in the front with a prominent volute decorated with carved acanthus
foliage resembling the spiral of a ram’s horn. Tucked beneath the front of
the “ram’s horn” a vase brimmed with flowers and fruit. Leaves and tiny
berries traveled downward from the centers of the volute.
The column itself
was slender, encircled with foliage on the bottom. The baseboard was
actually two pieces instead of one solid piece. The column rested between
the two pieces which were decorated with leaves that fanned from the center.
Beneath the baseboard, the harp’s base was a simple fluted pattern decorated
with a single simple flower in its center.
The harp’s action was housed in the neck and
covered with a decorated removable panel. Hand-painted chinoiserie decorated
the panel, as well as the other side of the neck and the ebony soundboard on
the body of the harp.
The panel and the
side of the neck where the tuning pins held the harp strings had gilded
low-relief carving. Two gilded coves trimmed the top of the shapely curve of
the neck and a gilded low-relief carving of ferns and tiny flowers decorated
the knee block.
My intention was to bring new life to the Naderman with a combination of
water gilding and oil gilding. Water gilding is the art of applying genuine
gold leaf to a meticulously prepared surface. Leaves of gold leaf are
applied with water-based adhesive and areas are highlighted by burnishing
them to a brilliant reflective luster, the hallmark of this beautiful art.
Oil gilding is a simpler process of applying gold leaf onto a surface coated
with an oil adhesive. The result is a luminous matte finish, but cannot be
burnished. This was my plan for restoring the Naderman:
- The acanthus ornament on the volute would receive the
brilliant luster of burnished water gilding while the low areas would be
- The vase of flowers and fruit would receive a combination of
burnish and matte water gilding. The leaves and berries would receive
the same treatment.
- The foliage on the column bottom and the baseboard parts would
also receive burnished water gilding.
- The flutes on the base front would be matte water gilded with
the simple flower in the center burnished.
- And lastly, the low relief carvings, coves and any other areas
would be oil gilded.
The Beginning (Some of the following photos show
work done on various harps)
Commencing work on the harp, the first step was removing the old gilding.
I began the stripping by thoroughly sanding all carved ornament down to the
The steps performed in the water gilding process are numerous; however
the process is defined by three major components:
- bole (also called burnishing clay)
- gold leaf
I begin the water gilding process by making the gesso.
Gesso is the foundation of gilding. It is made with two ingredients: rabbit
skin glue, a very strong natural adhesive and whiting, a fine white powder
made from calcium carbonate.
I put a measured amount of rabbit skin glue granules in
a container of distilled water to soak for several hours. I set the
container in a pan of heated water to gently melt the swollen granules into
liquid. Care must be taken to avoid overheating the glue for this can
destroy the glue’s adhesive quality. The container is removed from the heat
and the whiting is slowly added to the glue though a sifter. The glue and
whiting are slowly stirred until both ingredients are thoroughly combined
and then refined by pouring through a strainer. The gesso is ready to apply
on the wood. Before applying the gesso, warm rabbit skin glue is applied to
the harp’s bare wood and allowed to cure overnight. This creates a strong
bond between the wood and the gilding. It is so strong that removing gesso
can be a lengthy process. I brush warm liquid gesso onto the ornament layer
by layer. When the gesso cools it solidifies. The gesso is sanded, carefully
working the sandpaper over all the ornament to make a smooth, flawless
surface. The gesso is ready for the application of bole.
Example of gesso on a Wurlitzer column (left) and on a Venus Aquilan.
Bole, translated from Greek meaning “a ball of earth”, is a clay-like
substance which is applied onto the gesso. It serves as a substrate for the
gold leaf. It’s also called burnishing clay because it provides the burnish
for the ornament--the areas that have the bright, reflective luster. Bole
comes in a variety of colors such as red, yellow, grey, black, blue, and
usually purchased as a premixed paste. I mix yellow bole paste with gelatin
glue and distilled water in a small container set in a pan of heated water.
Several layers of the yellow bole are brushed on as a base coat over all the
ornament allowing each layer to dry before the next layer is applied. Next,
I mix red bole and cover the yellow bole with several layers. Carefully and
slowly the bole is brushed over the intricate details. A smooth and flawless
application is a must because any flaw on the surface of the bole will show
in the gold leaf. After the bole has completely dried, with a rough cloth I
hand buff the areas that will receive the burnishing to a smooth, high
Example of early Lyon & Healy column with yellow bole
Example of red bole on Wurlitzer column
Now the harp is ready for the gold leaf.
Gold leaf is gold beaten into delicate, translucent
leaves, so delicate that when picked up with your fingers, it will simply
dissipate. Hold it in the light, you can almost see through it. American
artist Charles Prendergast described gold leaf as “…like a half solidified
piece of sunlight”. Gold was originally beaten by hand by skilled craftsmen
undergoing a three step beating process. Gold can be beaten as thin as
1/250,000th inch. Today, gold is beaten in a two-step process with automated
Etching of beating gold to make gold leaf
Gold leaf comes in 3 3/8”x 3 3/8” square sheets packaged in a tissue paper
book. A book contains 25 leaves slipped between rouged tissue pages. A box
of gold contains 20 books--a total of 500 leaves.
To apply gold leaf onto the bole, I drop a leaf of gold onto a
gilder’s cushion, a pad covered with suede leather. I blow the gold
with a quick gentle puff to flatten the sheet. With a special gilder’s
knife the gold is cut to the needed size. I wet the surface of the
bole with a water-based adhesive called “gilder’s liquor” made
with distilled water and denatured alcohol with a tiny drop of gelatin glue.
Gilder’s liquor activates the glue in the bole to make the gold adhere. To
move the fragile gold from the cushion to the bole, I use a special wide
flat brush called a gilder’s tip.
Gilder’s tools: gilder’s cushion, gilder’s knife,
and gilder’s tip
The tip is brushed against my cheek or through the hair to generate static.
When the tip touches the gold, it adheres to the tip’s hairs and I lay the
gold onto the wet bole.
The gold leaf is laid piece by piece until the entire area I want to gild on
the harp is covered.
An early Lyon&Healy harp receiving gold
The gold is ready for burnish after at least an hour.
The Moment of Truth
The moment of truth appears when I begin burnishing the
gold. I use a burnisher, a tool tipped with a polished agate stone to
burnish the gold. With the agate burnisher, I gently press it back and forth
over the gold. This is not polishing the gold as many people would believe.
What’s actually happening is I’m pressing the gold against the smooth,
buffed surface of the bole underneath, a slow process. I press the burnisher
over the Naderman’s ornament concentrating on one small section at a time,
and the brilliant, reflective luster appears. A good burnish feels like the
gold is burnishing itself. It’s like capturing lightning in a bottle! When
the burnishing is complete, I apply another layer of gold leaf on top of the
burnished gold and burnish it again. The result is a deeper, clearer
brilliance. Lastly, I oil gild the low areas on the volute, the low-relief
designs, and the cove details on the neck.
Using an agate burnisher to burnish
on an early Lyon&Healy harp
The Naderman’s volute and vase after
The Final Steps
When the gilding is complete, the final step is sealing
the gold. The water gilding is sealed with lacquer and oil gilding sealed
After I had done that, Pat cleaned and repaired the
action and other mechanisms, and the Naderman was reassembled and restrung.
A new soundboard with chinoiserie reproduced by a
talented artist replaced the original one, which Pat mounted and framed for
the new owners.
(Chinoiserie photos courtesy of
Here is the completed Naderman harp:
I had the opportunity to meet the new owners of the Naderman when I
accompanied Pat on the delivery of the harp. They were a husband and wife
whose home displayed their passion for Oriental antiques. The Naderman with
its chinoiserie would definitely be a fit!
Reflecting on this experience, I think that the Naderman harp is my
“Crown Jewel”. I never imagined becoming a gilder, let alone having a harp
as beautiful as this come into my life. Gilding an instrument with such
beautiful, intricate detail challenges my skill as a gilder. I don’t work
the gilding: gilding works me. The challenge of gilding has made my inner
world expand and embrace new possibilities. I hope another one comes my way.
[After completing the article, Valeria wrote, “I’m about to start a new
harp project! I will be regilding a 1929 Lyon & Healy Style 26. The harp
came to Chicago and Pat disassembled the harp. The parts are in my studio
and ready for restoration. I’m excited!”]