This is a description of the “Water Gilding” process by Wies Norberg, covering this ancient and traditional method of applying gold leaf to complex and sculptural surfaces. It is suitable for any rigid surface that will retain the base coat, or “gesso”, such as wood, plaster, stone, etc. Objects gilded in this manner are suitable for interior use only. For exterior use, a waterproof size must be used, a process briefly described in another article.
This article is posted for informational purposes only and is not intended as a definitive guide to the subject. Neither the author nor the editor assume any reponsibility for any loss or harm whatsoever resulting from the use of this information. Copyright is retained by the author, Wies Norberg. Her written permission is necessary for any use of this material beyond the private viewing for which it was intended.
Gilding Part One: Preparing and applying the gesso
Gesso (“chalk” in Italian) is the base material for gilding and its ingredients and their proportionate mixtures vary to suit individual needs. Each gilder experiments constantly to achieve a consistent result that suits the surface he or she is attempting to gild. There is a lot of speculation as to the reason for gesso. I’ve heard that its primary use is to disguise the material underneath—yeah, ok! But this material is what absorbs the water when you gild, making the gold adhere. A smooth coat of gesso also provides a base for the brilliant shine that is brought about by burnishing.
Gesso is a mixture of calcium carbonate (whiting) and a hide glue. The proportions of this mixture depends on the gilder’s experiments. The addition of kaolin (china clay) makes the gesso softer and smoother to sand. What the gilder must do is prepare the surface by cleaning it and ensuring that no oils or other non water-based materials are present. Next the gilder brushes or sprays on approximately 8 to 16 coats of gesso, which is later sanded smooth. The gilder will sand out all brush strokes or drip runs, as well as reshaping details that have been filled in by the gesso. There are other alternatives to working up blood blisters from all that sanding, such as using a fine silk saturated in water and wiping the surface of the gesso with it. However if you try this be careful not to over-saturate the gesso, which would weaken the material’s adhesion to the surface and cause problems later. Until someone can recommend a better idea, I will still get blisters on my once-beautiful fingers. (I would like to grow my nails back some day too. Men have it so easy, they don’t have to think about such things…)
The main ingredient in the glue is rabbit skin. This material is perfect for the process because of its elasticity. There are many different proportions possible for this glue, so it’s up to the individual to mix it to his or her satisfaction. A typical recipe is one quarter of a cup of the dried glue added to 8 ounces of cool water, which you let soak over night. The next day you heat it indirectly, by placing it in a pot of hot water (not boiling) until the glue is totally dissolved. Keep in mind that you can vary the amounts to suit your specific needs. After that you add your whiting and—presto!—you have what we call gesso. For storage of these materials, use your refrigerator or the glue will decompose and stink the place up. When you need the material, all you have to do is heat it up slowly in hot water and use it as you go.
Another recipe makes an emulsion gesso, which some find easier to deal with than the previously mentioned type. Rabbit skin glue is an emulsifier, like egg yolk. If you add linseed oil and resin to the basic gesso (about 10% of the total volume of each), when the whiting and glue have cooled to about 90 degrees, the oils emulsify into the gesso quite easily. When trying any gesso recipe, try applying some to a scrap as a test, then check it for toughness and adhesion. It is necessary to have a strong glue due to the burnishing the material will have to endure. If it doesn’t have the strength it needs, the gesso will flake off in chunks along with the gold you worked so hard at putting on.
Gilding Part Two: Applying the Bole
Now that the gessoed surface has been sanded smooth and dusted off completely, it’s time to make what is called “bole”. Bole is the mixture of a very fine grade of clay and your glue. Mix whatever strength you are comfortable with, being mindful that having too little or too much glue mixed into the clay or using too weak or too strong a glue mixture can be problematic. Just be ready for things to not work out right away. The clay comes in dry cones that you can dilute yourself or in a premixed version. For beginners I strongly recommend the premixed, mainly due to the complexity of blending it on your own. I also recommend waiting until you get a little experience at it before leaping into the world of in-depth experimentation.
There are many shades of clay (dry cone or premixed) that can be mixed together to get a desired effect. The different colors are intended to accent the gold and create subtle differences that enhance the overall effect of the subject. Yellow is primarily used in recessed areas to conceal missed areas during gilding. (After a while you, ll stop using it because your gilding will be so tuned that mistakes or errors will become a thing of the past. ) Red is primarily used on the broad areas of the subject so as to create a warmth underneath the gold. Black is also used, but mostly on the extreme high points of an object so as to absorb some of the light. (The last thing anyone likes is to get blinded by highly polished gold as it reflects light.) There is also white, gray and also blue. For instance, if you want a terra-cotta color, mix a little yellow (and I mean a little at a time) into a portion of red clay and there you have it. After you have mixed this mixture into your glue, (slightly heated so it’s fluid—remember how I told you how to do that?) take a soft (and I mean soft) brush and apply a few coats of the bole. Allow each coat to dry before applying the next or you run the risk of taking up what you just put down. After the bole dries, you’re ready to put the “Gold Leaf” on.
Gilding Part Three: Handling the Gold Leaf
I must make this clear. Handling of the gold and laying it down on a wet surface is not an easy feat to do without making a ton of mistakes. Yes-you will just about kick the cat, mouse, dog and your husband. (Not necessarily so, but you’ll have those days—believe me!) In reference to those attempting to water gild a whole leaf at a time; I must express that everyone and I do mean EVERYONE, had a tough time getting the routine down. So don’t get discouraged. It takes approximately 2 to 6 months of practice before you start getting the technique under control; but when you get it you’ll be able to tell instantly.
I would recommend for beginners to start by cutting your gold into more manageable sizes. And when gilding, start at the top of the subject and work your way down. Also it would be a good idea to slightly tilt it so the water will run away from the area you are gilding. The reason for that is because if water runs over the top of the gold you just put down, it will stain the surface. When you burnish that area, the gold will remain a dull color. So remember, start at the top and work your way down.
When preparing to gild; the boled surface gets a little buffing from a short stiff-bristled brush. This removes the grit on the surface of the bole so you’ll have a smoother surface while gilding. Not much pressure is used when buffing (so don’t get crazy on me ok? ). Next you look over the subject and (I’ll use a sculpted object for this description) chart your course. You don’t want to have to go back to spot something and risk staining the gold, especially where sculptures are concerned. Framers don’t have to worry about it as much as someone gilding a sculpture would, but the concept still applies to them.Some gilders burnish the bole before applying the gold, to make the finish more brilliant when you burnish again later. A lot of people claim this is beneficial, but I tried it and didn’t see the difference between the two end results. (The only difference I felt was in my knuckles.) I am not discounting the idea, but I see no need to add unnecessary work.to an already labor-intensive process.
Gilding Part Four: Applying the Gold
Once you have your course charted, you break out your gilding equipment. A gilder’s “pad “ is used for cutting and handling the leaf. They are made of deerskin and vary in available sizes. I recommend the largest pad on the market; you’ll need the extra surface area for handling more than a few leaves at once. A gilder’s knife is used for cutting and moving the leaf about the pad. The edges are rough when sent to you and I would recommend getting the edges honed smooth. Be careful not to get a sharp edge or you’ll cut your pad to shreds. A gilders “tip” is used for picking up the leaf and applying it to the surface you are gilding. This tool is flat and about 3 and a half inches wide with soft hair protruding along its length . A “mop”, basically a soft-hair brush, will hold a good amount of water for distributing along the surface. You’ll also need a cup for the water and a box of 100% cotton balls. The last thing you will need is oil; in this case I would suggest a petroleum jelly, such as Vaseline.
Open a book of gold to a page containing a leaf. Either let the leaf slide out of the book onto your pad, or flip the leaf onto the pad while holding the page open (you’ll have to get a video on gilding to see that one in action). Use your knife to move the leaf around until it’s square on the pad so you can cut it. Sometimes you will have to flatten the leaf on the pad by gently (I stress gently) blowing on it. After it’s lying flat, take your knife, place it on the leaf, and with gentle pressure and a sawing motion cut the leaf to the size pieces you need . When you’ve cut the leaf you should make sure that when you remove the knife you draw it off along the cut line. Do not lift the knife straight up, since the leaf has a tendency to cling to the edge and this will cause the leaf to shred apart.
After you have cut up a number of leaves you are set. Take your tip and drag the hairs across the film of Vaseline. This will coat the hairs, which makes the gold leaf stick to it (no, static electricity does not cause the leaf to stick to the tip). With this stuff you use a very small amount. Find a place where you can easily pick up a trace amount of the goo on your tip. I use the back of my hand, rubbing the Vaseline until I have a thin film to work with. This is what actually makes the leaf stick to the tip. From here you are able to carry the gold leaf over to the area you are gilding. You will ruin the leaf by touching it, so be careful with the stuff—it’s delicate)
Now comes the touchy part. Touch the hairs to a leaf and pick up a piece of the gold. Now take your brush and brush water over the area that you want to place the gold on immediately. You may have to keep brushing water on it if it absorbs into the surface too quickly, because if the bole dries out before the leaf gets on there it will not stick; you, ll be too late. The water must be present on the surface when you lay the leaf down—or forget it! (I have wasted a lot of money by that error alone) After soaking the surface enough, watch the water absorb a few times until it occurs slowly enough for you to get the gold on it. Pay close attention to the speed at which the water disappears. When it’s slow enough, lay the piece of gold down and continue to the next one. While you are gilding other pieces, you have to gauge when the first piece is ready for you to check with your cotton.
Cotton is used to gently pat the surface of the gold when the water appears to have been absorbed into the surface, leaving the gold lying on the bole. The leaf is checked by patting gently with the cotton to ensure that the leaf will stick. On occasion when patting down, the gold is broken from checking too early and water is forced over the surface, staining the gold. The 100% cotton helps to minimize the amount of staining through its ability to absorb most of the water when this happens. The synthetic blends tend to repel most of the water and will make the damage worse.
No matter how long it took for the water to absorb at first, remember it will take progressively more time, since the material underneath is becoming saturated. Remember: pat down the gold gently; if you’re heavy-handed the gold will break apart. While you are patting down the gold, or “checking”, recheck your course and make sure you are not missing anything. It’s easy to stray off-course when you are gilding so be careful you don’t gild yourself into a trap. When starting out for the first time don’t stress out. Expect to do just what I am warning you not to do. After you make the mistakes, you’ll start fine-tuning your timing. After gaining some experience, you’ll be able to lay gold on the surface of the whole darned thing before it’s time to check the gold! After you have completed the gilding and checked the last piece of gold, the subject must dry thoroughly. I recommend leaving it overnight.
A few things are crucial for the gilding to go smoothly. Make sure there are absolutely no drafts present. I would suggest a private room with a Do Not Disturb sign on it. The reason is that the slightest draft of wind, like when someone walks by, will cause the leaf to blow all over the place. And if the leaf flaps around erratically while it is on your tip, when there are no drafts, then you have a static charge in the air. When this happens it can ruin a whole day that was planned for gilding. Get some static-guard from the store and spray the room down before setting up. Also the carpeting may have to be covered due to static charge buildup. Sometimes sprinkling water on the floor helps.
When you return the next day to your project that has (thoroughly) dried, you will need to buff the surface with a piece of sheet cotton. Here you will find out if the gold has stuck to the bole or not. Prepare to see all the gold wipe off before your eyes, but if it does do not panic; it happened to all of us several times before we grasped the timing concept. To help you understand this concept, I have thought up a comparison for you to picture in your mind: Three lumps of clay are sitting on a table in front of you. The first has been wetted down and is squishy and oversaturated with water. You push on it, your hand collapses it and slides off. The second lump is all dried out from being left out overnight. With your other hand, you push on this one; it is dusty and unyieding. The last lump is fresh out of the container. It’s moist and ready to be worked with. When you push your hand in it, you leave an impression of every fingerprint.
When you place the gold on a saturated area, you don’t want to check (pat down) the leaf too early or the gold will just mash before your eyes, like the first lump.
You also don’t want to check the leaf after all the moisture has left the bole, because the leaf will not stick to a dry surface like the second lump.
The trick is to check the leaf while the bole (which is a type of clay) is moist, like the third lump.
Remember that the bole has glue mixed into it, that is what helps the bonding of the leaf. When you wet the bole, you are refreshing the active ingredient: the glue. If it is dry, then it will not stick. That is why you should watch the water absorb into the surface a couple of times so you can get an idea as to when to apply the gold to ensure it comes in good contact with the properly moist surface.
If the gold leaf does wipe off, (I know a lot of time went into it and the gold is basically wasted), just write the incident off as a learning experience. When having to regild the areas that didn’t hold the gold, I recommend taking a small piece of the glue about the size of a pumpkin seed and heating it up in your glue-melting water. This should give you a little help in refreshing the glue strength on those areas. Be careful that you don’t use too much water at once or a bead of water might run and stain the gold around you. You still will have to check the gold so keep working at it. You’ll get used to it after a while.
Gilding Part Five: Burnishing the Gold
Now, if everything worked and you don’t have to redo anything, is the time to “wear” the surface a little and burnish the gold. If you’re as old as me, prepare yourself for muscle cramps in your hands when doing this part—plan on taking a few breaks and set yourself up with something to do while your hands recover. The “wearing” of the gold is to simulate age. prevent it from immediately looking much worse when handled normally, and to bring some of the clay’s color out through the gold to accent it. Materials for this process include rottenstone, pumice, steel wool and my favorite—a piece of an old wool blanket. Rub with this until you get just the right amount of the color showing through, then stop. Concentrate on the areas that would receive the most handling over a period of time. Other areas are best left alone; but wearing remote areas can bring balance to the overall effect of the piece. Forethought and professional discretion should be exercised. After you have worn the gilded surface to the desired effect, you can start burnishing it. Wear soft cotton gloves so you don’t leave oils from your hands on the surface that will also dull the gold. You use a burnisher, an agate stone that’s been shaped, smoothed, and polished, then mounted on a stick. Rub the gold with this, using a moderate amount of pressure in order to compress the underlying material, and watch the stuff shine up!
While you are doing this, you will be skipping some areas between each stroke of the burnisher which need to be gone over if you don’t want any dull streaks all over your nicely burnished work of art. Also be careful not to get heavy-handed and make the gesso lose its grip and flake off the surface. If this happens, you will have to reintroduce gesso into that area until it builds up enough to sand it flush with the surface and brush on one more coat, sand with 600 grit wet or dry paper to flush the edges, and spot a piece of gold over it.
Once the project has been finished, and you are staring at a brightly burnished gilded masterpiece, (believe me, you’ll call every one of them a masterpiece after all this work) it’s time to apply your patina. I’m sure you will probably resent the idea of smearing thinned down paint all over it, but sometimes it has to be done. There are all sorts of ideas for patinas out there. The trick is to use the right one for the subject you are working on. The finished gilded object sitting before you may have to be sealed in order to protect the gold from being removed during this process. However, I have patinated some gilded objects without having to seal-coat the gold. So good luck on your experiments.
For answers to questions you have, feel free to email me at: firstname.lastname@example.org
by Wies Norberg
© 2000, Wies Norberg