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GOLD LEAF MANUFACTURE
In November 1997, I toured the gold leaf factory of Giusto Manetti, Florence, Italy. Dr. Fabrizio Manetti explained to me how his company has produced gold leaf for 177 years. Only in the past 10 years, I learned, have they introduced mechanical gold-beating equipment into the time-honored tradition of manufacture.
Due to the secrecy of the craft, other gold beaters may have slightly different techniques and a slightly different product. Speaking of secrecy, security for this visit was understandably tight. It had taken me six years to get past the front door, so I faithfully complied with their rule forbidding cameras.
Gold Leaf manufacture progresses through 5 distinct stages: melting, rolling, beating, beating again, and packaging.
The melting stage involves reducing the gold from a pure 24-karat ingot to an alloy, incorporating sliver and copper, which improve the handling characteristic and prevent some "small troubles." Sometimes palladium or platinum are added for obtaining special colors.
The second stage is the rolling process, which produces a gold ribbon about 6 inches wide and 10 microns (1/100 of a millimeter) thick. This ribbon shape is obtained by heating the gold to 20 per cent less than the melting point, and then rolling it. The heat softens the gold. The heating and the rolling alternate until the desired thickness has been obtained. "The Germans," noted Dr. Manetti, "make their rolled gold thicker."
At the third stage, the gold beating begins. The gold ribbon is cut into square pieces and stacked in a pile of 600 to 800 sheets, with a special varnish-coated paper liner separating each sheet. This gold "sandwich," all of two inches thick, is placed under a mechanical hammer and pounded until the leafs spread into round shapes of nearly the same dimension as the liner paper.
In describing the process of gold leaf manufacture, Dr. Manetti described an interesting historical footnote. Twenty years ago he joined an English gold beater in examining an Egyptian funeral mask at the British Museum in London. He determined that the thickness matched that of his own gold after the first beating. "If the Egyptians used this process," reflected Dr. Manetti, "then people of a previous civilization probably used it."
The beaten gold is then beaten again. It is cut into 4 or 9 square parts and transfered to a plastic film, also about 6 inches square. Thanks to modernization, the plastic film replaces traditional beef gut, which once caused this stage to be a dirty job. This plastic film is varnish-coated as well, to prevent static "cling." A gesso powder (similar to talcum powder) also is used to keep the gold from adhering to the plastic. This time the sandwich, now called the "mould," contains 1500 to 2000 sheets of gold, undergoes a second stage of beating. Then the mould is ironed, and the gold attains its final thickness of .1 to .4 microns.
This gold has remarkable qualities. You can hold a sheet up to the light, and it appears to be nearly translucent. Yet when properly applied over sizing (and then polished), the same sheet of gold reflects light so vivily that the object it covers appears to be wrought out of solid gold.
Finally, the gold is packaged into booklets of 25 leaves, but this stage is hardly easy. While men may apply for this work, they seldom have the patience or dexterity for the task. In short, women are considered to be superior at it. I saw at least two rooms of women seated at rows of tables, completing this packaging process by hand.
First the oversized sheet of gold is removed from the "mould" and placed with wooden tongs on a leather pad. Then the worker uses a small, sled-shaped cutter to make two criss-cross passes over the gold. Next, the worker moves the square piece from the center of the leather pad to the booklet, again using wooden tongs. The rest of the gold is reclaimed with the help of a rabbit's foot. (This breed of rabbit is not used for luck. It comes from snow-bound Norway, and so grows long hair.)
In conclusion, Dr. Manetti commented that gold leaf manufacture has changed very little since the inception of civilization. In the last 30-40 years, technology has helped to shorten the manufacturing cycle. The substitution of plastic for animal skins in the moulds and the assistance of mechanical hammers are the most radical changes of recent times. Otherwise, gold leaf remains the same hand-crafted product that was produced in times of yore.
THERE ARE NO SUBSTITUTES FOR GENUINE GOLD
As Dr. Manetti said, traditional gold leaf has been beaten and gilded in the same hand-crafted fashion since the dawn of civilization. Except for minor refinements, the technique has remained unchanged. Why? Because the lustre of gold is incomparable.
Various substitutes have been developed and tried, which include bronze powder and reflective vinyls. Bronze powder has a promising reflective quality, which can look attractive in the absence of real gold, particularly on blue backgrounds. However, bronze (and copper) powder is prone to discoloration and must be be completely sealed by a clear-coat, or be sprayed on in a clear-coat to ensure durability.
Similarly, various vinyls have attempted to replicate true gold's reflective quality. One technique uses a silver foil covered by a translucent line. Another vinyl approximates the appearance of a matte deep-toned gold, exhibiting a slight sparkling quality. This vinyl has a tone and appearance similar to that of the spray-painted bronze product mentioned above; it can look handsome when outlined in white.
Regardless of their good qualities, these substitutes pale by comparison when real gold is diplayed next to them. Real gold can be modified during application to take on special qualities such as a high polish or lustre, a deep mirror quality, an "engine-turned" effect, or any combination of the above. Gilding on picture frames and reverse gilding on glass are specialized arts unto themselves. (We are all accustomed to seeing ourselves in mirrors, but few of us have had the remarkable experience of seeing out image reflected in a mirror of gold.)
However special the effect of gold may be, it is transitory unless protected. The gold leaf itself lasts well, but its thinness and relative softness are liabilities. Abrasion can wear down the surface, while weather and bird droppings can attack the sizing.
Part of the problem stems from the softness of sizing - it must dry slowly enough to retain a "tack" long enough to permit the laying on of gold leaf. During the period immediately following gilding, the product is especially tender. Depending on the type (there are "fast" and "slow" sizes), curing can take 1-2 days to cure, or months. During this time, a hangnail on your finger can seriously damage a polished finish.
Therefore, gilding on surfaces such as trucks, boats, and signs near pedestrian traffic often require clear-coating. This can be a delicate process in itself, for the gold is soft and the clear-coat is meant to be hard. Modern two-part varnishes contain strong solvents which can attack the sizing. Also, the clear-coat must be applied somewhat thickly in order to guarantee a durable film. The caution and the expertise required for the step of clear-coating are justifiably warranted.
Despite Dr. Manetti's observation, there does seem to exist a revolutionary new approach to the handling of "pure" gold - in this case the 22-karat SignGold. While this product (first formulated and marketed in 1992) does not have the built-in flexiblility inherent in custom gilding, it does aim to serve a niche well above the gold substitutes. Furthermore, SignGold, by design, radically reduces production costs and increases durability.
SignGold has 3 characteristics of great interest to traditional gilders. It's real gold, it cuts like vinyl, and it lasts BETTER than clear-coated gold leaf.
Unlike standard high-performance 2-mil cast vinyls (polyvinyl chloride), SignGold is manufactured with 1-mil cast Tedlar (a Dupont product made of polyvinyl flouride). Regarded by architects as one of the most durable indoor or outdoor surface protectors, and long used in the auto industry for to cover decorative panels and silver trim, Tedlar has been a standard outdoor protective laminate for 25 years.
SignGold corporation manufactures their product by the following process. They scratch or score patterns on the Tedlar similar to those used by professional gilders (engine turns and Florentine swirls among them). This becomes the backside, while the smooth side becomes the top surface. Next, genuine gold is heated at 2000 degrees Farenheit in a vacuum chamber, and shot in a vapor state onto the backside of the Tedlar film. Then the gold side is sealed (not laminated) and given a coat of acrylic pressure-sensitive adhesive.
Significantly, this process ensures that only one layer of film carries the gold to the substrate. If the gold were sandwiched between two layers of film, the system would be subject to movement, checking, wrinkling, and delamination. Since the SignGold technology employs a single layer of Tedlar film, the product might be described as "pre-varnished and pre-sized sheets of gold." A product which removes the headaches of clear-coating and guarantees durability for 10 years greatly helps the sign painter.
The square-foot cost of gold leaf in a book works out to approximatedly the same as SignGold. If you buy a pack (500 leaves) of gold leaf for $400.00, you pay 80 cents per leaf. Each leaf measures 3 1/8 by 3 1/8 inches, or about 10 square inches. On other hand, a 36 inch length from a 14-inch roll of SignGold contains 504 square inches and costs $39.95. That works out to about 8 cents a square inch, or 80 cents for a piece the same size as gold leaf.
Gold leaf is a fragile raw material, but SignGold is a nearly finish product. SignGold costs much less to apply, and it doesn't need to be clear-coated. Thus, with SignGold, you get a double savings on labor.
Other pro's of SignGold include the convenience of one-stop installation. Gold leafing outdoors requires at least two trips (if clear-coating is to be included) and an eye on weather conditions. On the other hand, the sign painter can custom cut pre-varnished letters on the computer and (if duly compensated) apply them in weather conditions that forbid gilding or clear-coating.
The con's of SignGold are that the reflective qualities of the gold are standardized. The mechanical regularity of the engine-turns can be a weakness in some applications while being a boon to others. For example, the handlettering artist can choose the size and location of the swirls in the letters, whereas the plotterlettering artist must "hope for the best."
In the final analysis, SignGold will find and define a niche that never existed before. In the process, specialized treatments probably will evolve, which will play to the strengths of the SignGold product.
INNOVATIVE SIGN COMPANY APPLIES SIGNGOLD
TO RUSSIAN CHURCH COPULAS
Industrial Maintenance And Construction (IMAC), Mount Carmel, PA blends innovative technology and creativity to solve age-old problems. Recently, IMAC refurbished several ornate Russian church copulas in the eastern United States which had fallen into disrepair due to high maintenance costs. When Frank Lawski, Jr. of IMAC was called to St. Michael Church in Shenandoah, PA several years ago, he initiated a renaissance in the salvaging of several similar churches on the verge of abandonment.
The gold leaf problem presented itself innocently as a single component of a larger problem in the St. Michael Church. Rebuilt after a fire 14 years earlier, this church suffered from moisture condensation due to inadequate air circulation at the roof's peak. Lawski recommended construction of a fiberglass copula with vents to draw off the humid air. Discovering that the high cost of decorating the copula with traditional gold leaf broke the budget, Lawski searched for an alternative.
He assembled the various substitutes for a field test, and found what has been repeatedly been proven over the ages, that real gold is incomparable and irreplaceable. There is no substitute. Bronze powders encapsulated in a clear coating can be useful, but their effect comes in a distant second when compared with the real article. Imiation foils also approximate gold's brilliant effect, but they do not match and do not stand up to long-term weathering.
Fortunately for Lawski, the signmaking division of IMAC supplied him with a sample of a new product called SignGold, which is made with real gold and performs like the adhesive vinyl that signmakers run through their plotters. When samples were hoisted in the open air during the field test, SignGold clearly matched the existing domes previously decorated with traditional gold leaf.
For a project of this size (the bottom of the dome to the top of the cross measured 18 feet), Lawski had to proceed cautiously. Lawski contacted the SignGold corporation and learned that this was a novel application for their product. The SignGold corporation answered that, with proper surface cleaning and correct application, they would warrant their product for 10 years.
Lawski learned that SignGold is manufactured with a single layer of Dupont Tedlar (R), a 1-mil cast polyvinyl flouride. Genuine 22-karat gold is vaporized at 2,000 degrees Farenheit and sprayed on the "underneath" side of the Tedlar. Then it is sealed (not laminated) and given a permanent acrylic adhesive coating. (For comparison purposes, high performance signmaking vinyls are made of 2-mil cast polyvinyl chloride, which is warranted for 5-7 years and may shrink slightly.)
To compare the costs of decorating the copulas with gold leaf, versus SignGold, it is first necessary to describle the cost and labor of the traditional technique. Gold leaf by itself does not have an exhorbitant cost. It has been beaten so thin during manufacture that you can see through it when you hold it up to the light. A sheet the size of the palm of your hand costs less than a dollar when bought in quantity (A pack containing 20 books with 25 sheets each has 500 sheets).
The cost of labor for applying the gold, however, can be prohibitive. The process of painting the sizing, waiting for the right "tack", and laying down the gold in piecemeal fashion consumes time. Consider also the painstaking process of polishing the gold and laying down additional "patches" while the size still holds its "tack". Next, remember that traditional gold leaf remains unprotected and therefore susceptible to normal abrasion and corrosion from bird droppings.
Alternatively, gold leaf may be clear-coated at significant additional expense. The trickiness of coordinating the compatibilty of the sizing (designed to dry relatively slowly) and clear-coat (containing strong solvents) poses one problem. The danger of the clear-coat cracking and flaking in the future creates another complication.
Given this description of traditional gold leaf which has been clearcoated as a background, it is possible to conceive of SignGold as a laminate in large sheets which matches it closely. Dupont's Tedlar is the "clear-coat", and the 22-karat gold has been "pre-gilded". The only labor requirement is that of "wallpapering" the laminate to the final substrate.
When IMAC's Lawski made the decision to proceed with SignGold on the St. Michael Church's copula, everyone concerned with the project took a deep breath. As it turned out, the concerns about material costs, labor costs, and durability were all answered favorably.
The material costs for using SignGold came to about half that of tissue gold leaf. Applying the SignGold to the copula took 2 people 7 hours - dramatically less than the labor for traditional gilding. (Lawski had received one quote from a contractor based on two people working for 28 days.) Three years after installing St. Michael Church's copula, Lawski found it to be in excellent condition.
There was no shrinkage of the Tedlar, and no edge of dirt sticking to the adhesive along seams and joints. No edges or ends were lifting up anywhere. Furthermore, where the SignGold crossed the seams of the copula itself, there was not cracking of the kind you would expect to see with paint coatings. And obviously, there was no fading. Comments Lawski, "I have no doubt that the SignGold will be there for many years beyond its orginal guarantee."
In subsequent years, IMAC has pioneered techniques for redecorating existing domes with SignGold. Besides the job in Pennsylavnia, Lawski has surveyed or worked on 80 domes spanning, South Carolina, New Jersey, Maryland, Ohio, Connecticut ,and Massachusetts.
They reinforce the structure of the dome on the inside with high-strength polyurethane foam. After they repair and seal the exterior, they apply a top "coat" of SignGold. One key to their success resides in meticulous prep-work, which ensures proper adhesion of the SignGold. In summary, this innovative product has found a new, unexpected application which showcases its many strengths. Materials and labor both cost much less by employing this process in the final analysis. However, to this writer (who has himself consumed several packs of gold over the years), the hidden advantage of SignGold lies in its durability. Considering that SignGold comes pre-laminated, the customer gets a no-cost protective clear-coating in the bargain. This advantage alone accounts for major savings.
SignGold cannot offer the custom quality of traditional gilding, but it does makes real gold more affordable. This innovative product defines a new niche in a field that has remained unchanged for millenia.
go to: Charlie Duane - published articles - gold leaf article