Gilded Glass
Laying The Gilded Foundation For Verre Églomisé
Gilding, the application of an extraordinarily thin layer of metal known as leaf to another surface for ornamentation feels at times as having infinite possibilities in its methods and techniques, some new, most quite old with its roots reaching back several thousands of years.
The gilding of glass combined with painting was practiced during Early Roman times, an artform brought back in vogue by 18th c French Designer and Framemaker Jean-Baptiste Glomy. It appears that Glomy practiced a specific type of painting and gilding specifically for framing prints whereby the reverse of the glass displayed a gilded border and colored paint. When others followed afterwards certain techniques similar in nature became known as églomisées as discussed in the book (1) Journal of Glass Studies. Terminology of Verre Églomisé by Rudy Eswarin, published by Corning Museum of Glass. This excellent scholarly study on the origins of the term Verre Églomisé can be found on the Digital Library website of JTSOR.
Glass Gilding: An Introduction to Verre Églomisé
The intent of both the Online and In-Person class offered by Charles Douglas Gilding Studio, Glass Gilding: An Introduction to Verre Églomisé, is to help students in their understanding of the essential requirements for gilding glass while learning some of the techniques used in Verre Églomisé work such as etching through the gold or silver leaf with a pointed bamboo stick. Learning the key elements for producing a successful gild, however, is necessary:
proper cleaning of the glass to remove any silicone or contaminants that might interfere with adhesion
Careful preparation of the gelatin Size, the aqueous adhesive used to adhere the gold or silver leaf o the glass
A good balance between brilliancy in the gilding and a good bond between the leaf and the glass
Typically, the class begins with a general overview of the topic of Verre Églomisé and glass gilding followed by preparing the size, cleaning the glass, and laying 6k white gold leaf to the back of the glass. During the in-person class this is when we break for lunch, allowing time for the leaf to dry (while continuing our discussions together over lunch at one of the local New York cafés or restaurants!).
Once we return to the studio we then buff the gilding if dry (or hasten it if necessary with a hair dryer) removing any little pieces of overlapped leaf and gently burnish the white gold with soft cotton. From here we explore the various steps we take depending on how we want the gold to look, either distressed, solid, or etched. We learn to spot gild by applying small pieces of white gold to areas we may have missed or where adhesion was insufficient which also gives students practice in learning how to cut leaf on the gilder’s pad.
Students discover how to double gild by simply applying another layer of leaf over the original layer which strengthens the solid character of the gilding while covering any small anomalies due to missed spots, pinholes, or cracks in the the leaf that can be covered more effectively by double-gilding rather than spot gilding which can leave behind faint ghost images made from the deposit of gelatin size.
We explore methods of abrading the gilding with handrubbing and pumice powder which gives and intriguing appearance when backpainted with oil-based paint showing the spiderweb-like veining in the leaf produced by the wrinkles created at times when the leaf is laid. A black paint is often nice for this dramatic effect although any color can be used.
Etching is produced by scratching through the leaf with the tip of the bamboo stick, creating a design in reverse either freehand or with the aid of a stencil or traced image for guidance. The image and the surrounding leaf gets backed-up with either a single or multi-colored application of oil-based paint which reads through on the front of the glass. The paint also seals the leaf offering a physical barrier against scratching as well as protection against oxidization of any tarnishable leaf that might be used including 22k gold leaf and less including genuine silver leaf. The backup paint also makes the gilding more reflective and solid since leaf, especially gold leaf, is somewhat transparent due to how thin it is beaten.
What Is Verre Églomisé Exactly?
The term Verre Églomisé has apparently drawn disagreement ever since its conception as to what it exactly refers to, whether the painting on the glass is strictly translucent or also opaque and whether it may be referred to as églomisé with or without the additional useage of gilding. Since Glomy’s time Museums and Institutions adopted the term to incorporate a wide variety of reverse painting, gilding, and engraving techniques which eventually would lead to the demand that the term be eradicated but to no avail. As quoted in the Journal of Glass Studies W.B. honey of the Victoria and Albert Museum wrote in 1933:
“The word was first adopted officially, so to speak, in a catalogue of the Musée de Cluny in 1852; when taken over by the Italians agglomizzalo it began to assume an air of respectable antiquity and became the customary term for all sorts of painting and gilding behind glass, of any date. Purists have denounced the term as an anachronism, as indeed it usually is, but in the absence of any other short name it is quite likely to survive.” (2)
Suffice it to say that the term has been a form of consternation for many scholars nearly since the beginning of its use while the term has evolved since the mid-eighteenth century to include all forms of gilding on glass. It would seem to have stepped away from its original intent although there doesn’t seem to be an agreement exactly on what that intent was. And so I think it’s safe to say that glass gilding is an excellent term to include all manners of gilding on glass while verre églomisé can accompany that world of reverse painting on glass with or without the use of engraved or etched gilding. ~
Another term that some glass gilders use for glass gilding is Water Gilding as it uses a weak gelatin Size made of gelatin dissolved in water to adhere the gold to the glass. However, I have a problem with using this term as there is already an ancient method of gilding wood such as frames, furniture, and architectural detail called Traditional Water Gilding, the earliest form of gilding and which also uses water throughout the process.
Exploring further into the terminology of gilding I would like to draw attention to Mordant Gilding, which is applying gold, silver, or other metal leafs to a prepared ground with a variety of water, oil, or vegetal-based adhesives. Some of these mordants are ancient such as gum ammoniac, garlic, or glair (beaten egg white); linseed-oil based oil size has been used for hundreds of years leading us to a growing contemporary selection of acrylics such as water-based adhesive (acrylic emulsion), Instacoll, Miniatum, and Miniatum Ink.
As gelatin used in glass gilding qualifies as a mordant perhaps glass gilding then is just another form of Mordant Gilding. Although that would only describe the gilded element of verre églomisé and not the painting or etching leaving us short once again in fully describing the beauty of this timeless artform. Perhaps we should just call it - magical! ~
An Experiment on the Electrical Properties of Gilded Glass
Dating back to 2009 I had a very singular and intriguing request concerning scientific research about the prospect of providing gilded glass to test its electrical properties. However, I didn’t know whether any of the traditional binders would interfere with the required electrical conductivity but accepted this opportunity to provide gilding of a large glassbeaker despite the unknown suitability of traditional glass gilding techniques.
The purpose of my client’s experiment was to repeat in the laboratory the process by which electricity produces lightning and to demonstrate that when water vapor condenses, the condensate is not neutral but negatively charged.
The Art And Science Of Glass Gilding
The first requirement was that the gold leaf be 24kt. I chose Manetti Double Weight purchased through Sepp Leaf Products in New York. Although gold leaf can be adhered with a variety of binders including oil size or glair (egg white), we chose gelatin dissolved in distilled water as used in verre églomisé. The rationale was that the residual binder remaining on the glass would be minimized with the small amount of gelatin used. I used four diamonds of gelatin to 300 ml distilled water.
The beaker needed to be gilded on the exterior including the bottom with a 1.5" distance from the edge of the gold leaf to the top edge of the glass. The gilding on the face of the beaker is the opposite of what is often referred to as Verre Églomisé which relates to Reverse Glass Gilding, the gilding of the back of glass as used in gilded mirrors and gilded glass tabletops. I simply taped off a section of the beaker 1.5" from the edge and gilded the glass upside down. For maximum coverage I double gilded the glass to allow for a solid covering of gold. After carefully packing the beaker with a layer of Saran Wrap and a multitude of cotton balls, bubble wrap, and packing peanuts, I sent the beaker on its way and waited to hear the results of my client’s project. Here is a brief description of his gilded glass experiment:
The electrical properties of the gilded beaker 24kt Gold Leaf on Glass: “An experiment of the electrical properties of gilded glass were better than expected. The gold surface is used to collect water condensate. Ice water is put inside the beaker to make the gold surface cold. Dew forms on the gold if there is enough humidity. This allows the investigator to demonstrate whether, when water vapor condenses, the condensate is neutral or negatively charged.”
It was fascinating that lightning was indeed produced during the experiment. As a gilder, another main finding of interest is that when electrical conductivity is required, gelatin in distilled water is a successful method of adhering gold leaf to glass. ~
Glass Gilding Classes
For those interested in studying gilding Charles Douglas Gilding Studio offers both In-Person and Online Classes including the popular : Glass Gilding: An Introduction to Verre Églomisé. Visit the website page Gilding Class Information for more detail or go to the Book A Gilding Class page for an up-to-date class schedule and Registration.
1.Eswarin, Rudy. “TERMINOLOGY OF VERRE ÉGLOMISÉ.” Journal of Glass Studies, vol. 21, 1979, pp. 98–101. JSTOR, http://www.jstor.org/stable/24190038. Accessed 11 Jun. 2022.
2.W.B. Honey, "Gold-Engraving under blass, The ConnoIsseur, 92. December 1933, pp. 2-375.