Lured by the siren call of gold, I was delighted to spend a weekend last November with Pacific Scribes, studying “Gilding ABCs” with Judy Detrick, an artist whose immaculate work and clear devotion to historical sources I have long admired. Manuscript gilding, the laying of gold leaf on vellum or paper, requires special consideration and care. For me, the unexpected and true pleasure of this workshop was working with materials which were, for the most part, used by scribes hundreds of years ago. We could clearly identify the materials we used as animal, vegetable or mineral.
Techniques used by medieval scribes are documented in two manuals of the time, Il Libro dell’ Arte, and De Arte Illuminandi (both translated by Daniel V. Thompson, Jr. in 1933), from the late 14th and early 15th centuries, the “golden age” of manuscript gilding in Europe. These are the methods we worked with, with some modern variations, notably the substitution of titanium dioxide for the toxic white lead.
Judy began by telling us that every calligrapher frets about his or her gilding. The renowned Harrison Collection of Calligraphy in San Francisco’s main library has work by some of the most accomplished scribes in the world. If they come back years later to see their work in the collection, they are all, to a one, checking on the condition of their gilding.
Judy brought samples of small gilded letters, as well as mistakes and trials of techniques with working notes next to each. The only prerequisite for the class was perhaps to bring a beginner’s mind. There were plenty of experienced teachers in the class as well as some who were gilding for the first time. The class structure and progression was very well organized. All materials including paper and gold, and ingredients for the various sizes, were provided. This really helped speed us right into mixing the recipes and gilding with little prep time.
The plant materials were gum ammoniac, garlic, honey, sugar, and gum arabic. The minerals were titanium dioxide, slaked plaster (calcium sulfate dihydrate), Armenian bole, the metal leaf itself, and more minerals for burnishing (most commonly agate and hematite, but a stainless steel spoon will also burnish well).
Animal material in this workshop was limited to rabbit skin glue (in the form of crystals to hydrate), though fish glue or hide glue are also traditionally used. Judy had a story about using an actual dogtooth as a burnisher, as recommended by the medieval manual, from an old dog of theirs who had the tooth extracted. The canines of any flesh eater will be very, very smooth, which is what you want to polish the gold.
Working with these natural materials makes one sensitive to the environment, the interaction between materials, humidity and temperature all playing a part in the process. I think perhaps gilders develop a feel for the work. Certainly some workshop gilders developed a desire for a spaghetti dinner while gilding onto the garlic base, which when breathed upon is quite aromatic!
Laying the base (seat/mordant/glue) smoothly is the hardest part. Make with distilled water to be sure of the cleanest mix. Judy had us work on our wet-in-wet technique to achieve the smoothest possible surface and learn to avoid the ever-dreaded air bubbles which have ruined many a piece of otherwise fine gilding. Always wet the brush in water first to prevent the liquid from running up into the ferrule. STIR the fluid with a toothpick; don’t plunge the brush in. When finished, clean the brush right away on a glycerin soap.
Armenian bole is used to cover the back of the letter tracing to transfer it to the good paper. Use a fine brush in the 0-size family to lay the base. Some find using a glass pen gives good control for this task too.
Choosing the proper mordant for the project is important. For use on a turning page, flexibility is a must. More rigid mordants may be used for two dimensional work that will be framed and not handled.
Tiny glass communion cups were the perfect size and shape to work with small amounts of fluid.
Being in a laboratory environment made it easier to see and thus learn the technique of making our own patent gold using loose gold leaf, which is thicker than the prepared patent gold already adhered to the carrier paper. Use .003 mm thickness clear polyester film (known variously as Mylar or Dura-lar), cut to a slightly larger size than the gold square.
Because loose leaf gold is so thin and will jump with a breath of air, the first step of opening the packet of gold to a single leaf is an exercise in slowness. With practice, loose gold can be successfully straightened or picked up and laid with a tweezer.
Carefully lay down the film on the gold leaf. The accompanying tissue helps control the static electricity, which is what transfers the gold to the film without an adhesive.
The flash of gold! After gold adheres to the film, carefully cover it with the tissue. Replace in packet. When ready to use, cut a piece of the film with the amount of gold leaf you want. Check carefully which side you are using; it’s easy to put the wrong side down. Wait a while before applying a second layer if necessary.
We practiced gilding with gold leaf, silver leaf, palladium leaf (a precious metal, close to silver in color, but will not tarnish), loose copper and loose imitation gold. Different bases worked better or worse for different metals. Some bases prefer loose leaf gold, some are fine with patent, some are better in lower humidity, some better with imitation metals, some can be burnished well and some are ruined by it. We worked with various recipes of gum ammoniac, garlic, and a gesso with the traditional ability to be lightly scraped and burnished, before laying the gold.
Judy showed us a piece of seccotine, made from fish skin and used to make fish glue, which appears in some traditional gesso recipes. It was also used as the flexible window coverings in horse-drawn carriages!
Here Judy is measuring honey by the drop, a trickier thing than it sounds, given the nature of honey. The proportion of sweetener (honey or sugar) can be adjusted in the recipe depending on the humidity of the work area. Too much will spoil the gilding, not enough and it won’t stick. A drier climate will want a little more honey in the recipe. When measuring for mordant recipes, use the smallest spoon you can find to avoid making more than you need. A salt cellar spoon works well for this.
Have a very clean work area, no grease, glue or water. Wipe your tools with rubbing alcohol to get rid of grease from hands or any debris. Prepare your space for gilding, with all your tools at the ready. Keep the paper absolutely flat on a very smooth surface; a plate glass or marble surface is also cold which will aid the dew point when laying the gold. Let everything dry naturally by air.
A freshly gilded letter, with the edges not yet cleaned up. Judy recommended that it is best to wait a little while before brushing away the excess to give the humidified base a chance to thoroughly dry.
Another interpretation of the same letter, showing the rich power of outlining with gold.
Perhaps the most important information I learned was to use a hygrometer to measure the humidity in a room where you will work. I have since gotten a good digital one online for about $10. Humidity is KEY. The optimum humidity for gilding is between 63 and 73 percent. The dew point is best in the morning, making it the best time for gilding. One trick Judy uses is to put the paper with base applied and dried into her refrigerator humidifier drawer for twenty minutes. There are workarounds for the dry climate that we live in. The reason breathing on the base alone will not give good results is that the substrate often needs to be humidified also.
I was grateful to learn some tried and true techniques for achieving success in gilding. The “ancients” had more time for this than we do. Gilding asks us to slow down, have patience, let materials humidify and dry in their time, not ours. With all the little containers of ingredients and mixes around, the room began to have the feeling of an alchemical lab. If we had been using traditional gesso made with white lead, we really would have seemed to be accomplishing the alchemist’s task of turning lead into gold!
Many of the specialized supplies mentioned in this article are available from John Neal, Bookseller to Calligrapher and Bookbinders, in the Gilding and Gold Leaf section. Photos of this workshop by Jessie Evans, used with permission. Many thanks to all who contributed to this enlightening workshop!