Sunday, April 11, 2021

A Word on Mordants

Mordant Gilding is a term used in gilding that relates to the use of an adhesive medium and considered an 
23k gold leaf on leather with acrylic emulsion

alternative method to Traditional Water Gilding. There are various mordants that we can choose from when gilding although Oil Size and Water Based Adhesive (a white acrylic emulsion such as the Sepp Leaf Workshop brand) are the two most popular in contemporary gilding alongside Instacoll and Miniatum by Kölner.

I also think of glair and gum ammoniac as mordants, two very old bonding mediums used for adhering gold leaf to paper and glass. Glair, discussed by Ceninni in his 15th c Treatise Il Libro Dell’Arte, is beaten egg white mixed with a little water and allowed to sit out overnight and the froth removed the next day. It provides a strong bond and when weakened with additional distilled water it’s brilliancy on glass can rival that of the more often-used gelatin size as we have seen in our églomisé/glass Online gilding classes.

Gum Ammoniac, a gum resin that exudes from the stem of the herb Dorema Ammoniacum can be found in Iran and Northern Africa. It is used by Calligraphers and historically goes back centuries for use in Manuscript Illumination. Through my own exploration I have found it to also be a candidate for gilding on glass to achieve a bright gild.

For those seeking ways to gild on leather, glair has been the traditional medium for bookbinding and bookedge gilding. However, I have also found acrylic emulsion to be a quick and decoratively successful way of gilding the smooth side of leather which, showing through my recent testing, to be a flexible mordant for leather. ~

Note: For those interested in an entry level introduction to the art of bookedge gilding a Zoom! Online 4 session class is scheduled through Charles Douglas Gilding Studio October 6-27, 2021. Registration is currently open at

Monday, August 17, 2020

Zoom! Online Gilding Classes

This September ushers in a new (ad)venture: Online
Gilding Classes! This is made possible through the use of Zoom, one of a number of Conferencing software apps which allow from one-on-one personal tutoring to an Online classroom size of any number, whether small groups or large. 

Our newsletter members and students make up an exciting gilding community extending from England, Ireland, and Sweden to New Zealand, South Africa, and all across the US so it’s wonderful that we can all join in as we explore these beautiful, ancient methods of gold leaf gilding. This is welcome news for those in need of an option to the classroom setting or as a convenient way for students to supplement their gilding education.

This new Online format provides a full Program of The Gilding Arts with multi-lesson courses in Traditional Water Gilding, Mordant Gilding, Glass Gilding/Verre Églomisé, Gold Leaf Restoration, and Gilding and the Antique Dutch Black Finish with Masterclass Tutorials in subjects such as Preparation of Gesso Putty and Mould-Making and Casting ; Toning of Gilded Surfaces; and the series Gilding in the Sacred Realm for Buddha Gilding , Icon Panels, and Liturgical Art. 

Shorter one hour Tutorials focus on specific areas of gilding for technical development such as using the gilder’s pad, knife, and tip effectively when working with loose gold leaf; solving issues such as troubleshooting picking up gold leaf with the gilder’s ‘tip’ and removing water spots on burnished water gilding.

Students will have the opportunity to enroll in the Full Program which will become available in early 2021, allowing enrollment in each online class, Masterclass, and Tutorial. Students may alternatively choose to register for any Course, Masterclass, or Tutorial separately.

Fall, 2020 Classes are now available for Individual Registration including Traditional Water Gilding, Gilding for Works of Art...a Study for Fine Artists, Gold Leaf Restoration, and the Masterclass Tutorial: Sacred Gilding: Gilding the Buddha.

The first step for those interested in the Online Gilding Classes is to download the free Zoom App on your chosen device and become familiar with how the program works. Zoom is fairly easy to use but it is still a good idea to become comfortable with using it before classtime. It is also recommended to register early to get fully prepared with any tools, supplies, or materials that you’ll need to acquire.

How the Online Gilding Classes work:

  1. Download the Zoom App at . The zoom program will default to the language of your computer’s operating system. The Home Page will direct you to download a Free version of the Zoom Application.
  2. Register for the Gilding Class or Tutorial of your choice. Students may Register at or through The Gilding Arts Newsletter.
  3. Once a student Registers, students will receive a Confirmation of their Registration with a Zoom Link to the class.
  4. Student clicks the Zoom Link in their email five minutes before class time begins. 
  5. Student will automatically be entered into a waiting room on Zoom. Each student will be entered manually into the Online Classroom by the Instructor (Charles) before class time begins.
  6. Once all students have been ‘entered’ into the Zoom Class the classroom will be locked by the Instructor as a safety protocol to ensure that our gathering is limited to enrolled students only.
  7. Class times are Live from Seattle, WA and are specified as Pacific Standard Time. Students will need to adjust to their local time. (For example, a class that begins at 11:00 am PST will be 7:00 pm in Ireland, GMT+1).

Major Courses meet once a week for approximately 90 minutes per lesson. This has been designed to allow students to be challenged without being overwhelmed. Students have the option of using their gilding tools and materials to work on a project while following along with the Instructor or to simply watch and take notes during that day’s lesson. Homework will be issued each week.

Upon registering students will be provided through email any Gilding Recipes pertinent to their Course and a copy of the Lesson Plan and homework assignments. Students will also receive a tools and materials list and suggested projects to work on during the course of study.

Efforts are underway to provide for recording of all Courses and Tutorials through Zoom to allow access to Video Archives to registered students. This will be a large benefit to the student body. Announcements will be made through The Gilding Arts Newsletter once this option becomes available.

Both Classroom and Online methods for learning gilding have their own benefits and opportunities and I am grateful that we can join together on this creative journey!

~ Charles Douglas, 
Teacher and Instructor

Sunday, April 12, 2020

A Primer for Aspiring Gilders: Methods, Binders, and Terminology

To many of the uninitiated, intrigued by the beauty of gold leaf, one of the first questions I hear is “what makes it stick?”. It’s actually a long answer, depending on the method of gilding, historical reference, and personal choice.

Gilding, which is the application of a metal leaf to another surface is comprised of three main methods: Water Gilding, Mordant Gilding, and Glass Gilding/Verre Églomisé. Water Gilding is used primarily on wood although can also be performed on plaster, hydrocal, and a mould-making material known in the Framing and Furniture world as Compo. Mordant Gilding which includes such adhesive agents as oil size and acrylic emulsion is designed for any non-porous surface from sealed wood and glass to stone and walls. Glass Gilding can be performed on either the front or the back of glass, from mirrors and tabletops to decorative glass sculptures and gilded and painted sceneries of age-worn Grandfather Clocks. 

Within these methods lie the techniques used for Byzantine, Russian, and Greek Iconography, Manuscript Illumination, 13th-18th c Florentine gilded panel paintings, the gilded architecture of Cathedrals and Domes and Palaces, the ornate picture frames of French, Italian, Flemish, and early American design, Asian temple woodcarvings, Tibetan metal work, the decorative effects of raised gesso for calligraphy or its use on frames and furniture in the form of pastiglia, or the beauty of paint over gold and etched away in a method known as sgraffito, or the gesso treatments of granito.  The uses of gilding throughout the centuries seems endless.

Traditional water gilding generally involves rabbit skin glue and/or gelatin; glass gilding/verre églomisé uses a food grade gelatin for bright gilding or oil size for contrasting matt sections although glair - beaten egg white - can also be used as described by Ceninni in his Il libro dell’Arte for religious reliquaries which also leans matt, depending upon the strength; oil size is a popular bonding medium in mordant gilding alongside other mordants including garlic, gum ammoniac, and contemporary acrylic emulsions. The use of these mordants extend from oil gilded interior and exterior architecture to the application of glair and gum ammoniac for manuscript illumination and bookedge gilding.

Each of these bonding mediums carry their own characteristics and purpose of use. Referred to as Size, many mordants such as oil size and acrylic emulsion (sold as water-based adhesive) are applied topically to a non-porous surface and allowed to dry to a slight tack on which the gold, silver, or other precious or non-precious metal leaf is applied. Both of these adhesive materials are considered mordant gilding. While we often hear of the popular term oil gilding, there is no separate term other than mordant gilding for gilding with acrylic emulsion and despite it being water-based it would be incorrect to refer to it as water gilding, a completely different method of gilding rooted in antiquity dating back over several thousand years. 

Traditional water gilding involves a protein binder throughout the process. My method of practice begins with preparing a 10% rabbit skin glue (rsg) solution: 1 part dry granules to 9 parts distilled water. Once the granules soften overnight they are heated in a double boiler until dissolved, the mixture never surpassing 120F to avoid destruction of the enzymes which would affect the adhesive quality of the glue. The wood object is then coated with a layer of the heated size and left to dry 24 hours, allowing the wood time to stabilize from the hydration.

The Rabbit skin glue solution is also used to prepare gilder’s gesso, a combination of 10% rsg, additional water, and calcium carbonate which is applied to the sized wood. The 10% rsg is then used in the preparation of the clay bole (a 10% solution of gelatin can be used for the bole instead of rsg as a matter of choice) which is applied over the gesso

The term gesso is used to convey foundation or ground. As used by the gilder it is most often comprised of rabbit skin glue, calcium carbonate, and distilled water. I have recently come to refer to it simply as gilder’s gesso to help differentiate it from other forms of gesso such as oil or acrylic-based. They are all referred to as gesso which can be confusing as the term is shared but the materials that are used in their manufacture are quite different. Although they each form a ground, a painter will use gesso to isolate the canvas from the effects of oil paint while a water gilder will apply gesso to wood to fill the grain and burnish the gold to a high lustre.

During water gilding, the gold leaf is laid over the clay bole once the bole has been sufficiently hydrated with water and alcohol, reactivating the glue in the clay which bonds the leaf to the surface. The leaf is then later burnished to a beautiful brilliancy. Often the gold leaf is left matt in specific sections of the gilded object for contrast to the burnished areas.

Clay bole is obtained as either a dry cone which gilders will then grind or tumble in a ceramic tumbler as I do with water and tumbling stones until creamy or it can be purchased pre-mixed where the clay has already been tumbled and mixed with water. This clay is then combined with a certain amount of dissolved rabbit skin glue or gelatin and applied over the gesso that has been sanded smooth. The clay provides a sympathetic color under the gold or silver leaf and aids in the effectiveness of the burnishing with an agate stone burnisher.

Gilders will often use the terms Clay Bole, Clay, or Bole interchangeably. Intriguingly, this holds true whether the clay bole is in its raw dry cone or pre-mixed state and whether or not it has been combined with the glue size. This is important to note since protein binders such as rabbit skin glue and gelatin have a short shelf life once mixed with water and should never contaminate the raw form of the clay bole which normally sits on the gilder’s shelf as it will turn the container of raw clay rancid and useless, it should only be used to create what I call prepared bole - the solution of clay, water, and glue which is used while gilding and stored in the refrigerator when not in use. 

Protein binders such as rabbit skin glue can last many months in their dry state when stored in a glass container and cabinet but breakdown fairly quickly once combined with water. Depending upon the temperature setting and condition of refrigerators, two weeks is generally a good guideline for maximum life of the prepared glue, whether in the form of the 10% water and glue size, the prepared clay bole, or the gesso. When any of these prepared materials deteriorate, which could be between 2-4 weeks in the refrigerator, the prepared glue size, clay, or gesso will develop a soft, watery texture and eventually a strong odor if left passed their prime due to the presence of the rsg or gelatin as they are both protein binders and should never be used once deteriorated since the adhesive quality will be adversely affected. 

The method of mordant gilding with either oil size or acrylic emulsion is less time intensive than traditional water gilding although each step is nonetheless important to be done correctly to achieve an attractive gild and to avoid any stressful mishaps. 

Unlike water gilding which requires a porous surface, mordant gilding requires a non-porous surface. Technically, raw wood could simply be given numerous coats of shellac to reduce the porosity on which oil size or acrylic emulsion can then be applied. Once the size dries to a tack the leaf is laid and gently compressed with either a soft pounce pad or light pressure through the thin rouged paper inside the gold leaf booklets or whatever is the gilder’s preferred method for smoothing the leaf. However, although a porous surface can be made non-porous there are other steps a gilder can take to create a more attractive gild than simply gilding over shellac-sealed wood. 

I often apply several coats of gilder’s gesso to wood frames and furniture to fill the grain, sand the gesso and apply enamel paint as an undercoat before oil gilding which provides a nice foundation free of the presence of wood grain while the paint seals the porous gesso and offers an attractive color under the somewhat translucent gold leaf. Other preparatory treatments are often necessary for other surfaces such as metal, especially for exterior work for successful bonding and longevity.

Gilding on glass is a method that I often refer to as Glass Gilding or by the French term Verre Églomisé, named after the 18th c French Dealer and Restorer Jean-Baptiste Glomy (1711-1786) who reintroduced the ancient Roman technique of gilding and painting on the back of glass.

As a weak size made of gelatin dissolved in water is used, some refer to this method as water gilding which I refrain from to avoid confusion with traditional water gilding. The form of gelatin used for glass gilding today comes in the form of a clear, short rectangular sheet with perforated diamond shapes for ease in measuring. Pharmaceutical capsules have also long been used and some gilders prefer these although in either case, the gelatin should be stored in a glass jar in a cool cabinet. It is best to use fresh gelatin as age can affect adhesive quality. A clear, crisp snap of the gelatin ‘diamonds’ is a good indication of fresh quality. 

For the beginning gilder it is perfectly good to choose a path of specialization in a particular area of gilding, whether as a water gilder of frames or furniture, a hand-letterer on glass, a manuscript illuminator, or a restorer of gilded antiques. Whether someone chooses to specialize or to become proficient in a variety of methods and techniques it’s beneficial to acquire an overall knowledge of the various forms of gilding, their history and purpose of application. It can be helpful in a business context and in the sense of self as an artist, in one’s confidence, choices, and opportunities that may come along. ~

Sunday, June 10, 2018

Traditional Water Gilding Class, New York, June 20-22, 2018

There are many opportunities available right now for learning a variety of gold leaf gilding techniques. Two classes for New York this month are sold out but new sessions will be available in October in New York and even earlier in Seattle. Meanwhile, for those interested in the beautiful method of Traditional Water Gilding there are a few seats available for June 20-22. Registration is available at Or through the Gilding Arts Newsletter. Drop me a note if you have any questions. Hope to see you in Manhattan!

Saturday, February 24, 2018

Gilding: Using the Gilder's Pad~ Charles Douglas Gilding Studio

Creating a custom URL for my Youtube Channel, just four more subscribers needed. After 26,000 views on this clip I figured it was about time ;). ..Charles

Monday, December 18, 2017

Gilding in...Seattle

It's a true joy to be working with some wonderfully talented painters around the country in this popular gilding class. And now an additional pleasure to be presenting it for the first time at Artist & Craftsman in Seattle ~ join us if you can!