There are many ways to approximate the look of gold, but nothing quite compares with the "real thing". The term gilding, according to Webster's Dictionary, means
| *size - gum ammoniac (the sap of the acacia tree), garlic juice or glair. |
| *gold leaf - 23k loose leaf or patent leaf ( gold attached to a paper backing for easier handling) |
| *glassine paper - A special type of paper that gold does not stick to. Used for storage and placement of gold, or for burnishing through. |
| *utility knife - to cut leaf |
| *tweezers - to place loose leaf on size |
| *drinking straw - to direct air onto size |
| *burnisher - firmly pushes gold onto size and smoothes out the surface of the gold |
| *paint brushes - to apply size |
| *large, soft brush - to sweep excess gold leaf off of project |
How to prepare dried gum ammoniac crystals for use as a size
Place about a tablespoon full of crystals in a small jar or shot glass. Pick out any unwanted matter (such as twigs). Cover with distilled water and allow it to soak overnight to 24 hours. This next part is really messy and sticky. Strain the liquid through a piece of pantyhose into a clean vessel. Strain again into a glass or jar that you will be using for storage of any unused size. Mix in just a small amount of paint to allow you to see the size after it has been applied to your surface. Yellow ochre or red (in imitation of armenian bole) for size used to gild with gold. Use blue color when gilding silver. Household ammonia or calligraphy pen cleaner will remove gum ammoniac size from your fingers, glasses and even paint brushes.
Any left over gum ammoniac may be stored and reused. Some people use a screw top jar and keep it in the refrigerator. This is great if you plan on using it within a couple of weeks. Any longer than this and you may have to scrape mold off of the top of your size. It is still usable.
Another method is allowing the size to dry completely before storage (covered or uncovered). The worst that will happen is you will have to dust the size before you add distilled water to reconstitute it.
Raised Gilding
Raised gilding is a similar process to that used to lay flat leaf. The main difference being the "glue" used. Instead of a size, a layer of gesso about the same thickness as your paper is built up with a paint brush. Several thin applications are better than one heavy one. The gesso is allowed to dry (several hours at least, but overnight is better). Then it is trimmed and sanded or burnished if needed. The rest of the procedure for laying gold is the same as flat gilding...It is re-moistened by exhaling on it and lightly burnished through glassine paper. Any loose bits of gold are brushed off. When completely dry, the gold is then burnished to a mirror gloss.
Although changing what you stick the gold to the paper with seems like a slight modification, there are many problems that may be encountered with gesso that aren't an issue with the sizes used in flat gilding. Something as simple as a lack of humidity in the air can affect whether your work will turn out to be a masterpiece or a total flop. The amount of moisture in the gesso at the very moment the gold is laid on top is a key factor in determining whether your gold will stick...or not. Another problem is making gesso that is not sticky enough to hold the gold to the gesso. If in doubt, too much is better than too little. Honey or sugar are added to the recipes to impart a bit of stickiness as well as allows for a less brittle gesso.
So if gesso is so hard to work with, why do people use it? Paper is made up of many small fibers pressed together. Vellum has an uneven texture to it also. The only way to achieve a mirror polish with gold leaf is to apply something on top of your paper or vellum to smooth out the surface so that the gold leaf will not mimic the imperfections. Gesso is a time proven way to do this. There is also the added appeal of being able to tool, stamp or emboss designs into raised gesso.
| 1-2 teaspoons - distilled water |
| 6-12 drops of warm honey |
| 1 teaspoon - hide glue liquid (woodworking glue) |
| 1 Tablespoon - slaked plaster (neutralized plaster of Paris, chalk, or calcium carbonate) |
| a touch of paint - Armenian bole (jewelers rouge) or yellow ochre |
| a disposable bowl and spoon or ones dedicated to making gesso. I use a small ceramic mortar and pestle. (It is very convenient for breaking up any lumps in the gesso) |
Mix together *1 teaspoon* of the water, the hide glue and 6 drops of honey. Add the liquid to the slaked plaster and mix it together. Get all of the lumps out. Add extra water a little at a time if needed. If using dry armenian bole, mull it with a bit of water to make a liquid to add as a colorant to the gesso. Adding dry ingredients now will make lumps. Tube paint may be added directly to the gesso. Test the gesso to see how it works. This may take several attempts and is actually the most time consuming and often frustrating part of making gesso. You may find that the recipe needs modified a bit (see problems/solutions section). Gesso changes with the weather ... literally. Once you get a satifactory gesso you can use it immediately or pour it onto plastic wrap in little spots or "buttons" and allow to dry.
Gesso buttons should be stored in an airtight container (35mm film canisters work fine). To reconstitute: place the amount of gesso desired in the bottom of a shallow glass or very small glass bowl. Place a few drops of distilled water on top. Let it sit for a while then place a piece of plastic wrap over your finger and break the gesso apart. Repeat this process until the gesso is completely broken down and is smooth enough for you to use.
It takes a bit of practice to make and use gesso. Constant attention is needed to keep the proper consistency. The ingredients will separate if not stirred during use. The water evaporates and will need to be added every once in a while. Sometimes the results are out of your control. Expect and accept the imperfections that WILL happen. Remember, the medieval scribe had to deal with all of these factors too. Even in museum quality pieces you will see the same mistakes over and over. Learning what causes the mistakes can often lead to learning how to prevent them.
Gold will not stick
*If the gold lays down nice, but falls off when you touch it, (sometimes in large flakes) the cause could be not enough moisture. Try applying gold again, paying careful attention to how much moisture is in that area. You may even have to apply water with a paint brush. (A common problem in low humidity - winter)
*If the gold will not stick to the gesso, but the glassine does. Your gesso is too wet (either with too much water or honey) Wait a while for the gesso to dry out a bit and try again. If the problem was too much water, try not to get the gesso as wet next time. If the problem is too much honey (the gesso will be pliable when completely dry instead of hard and chalk like) sometimes a little bit of slaked plaster mixed into the gesso will remedy this situation.
*If the gold will not stick no matter what you try. Larger areas can sometimes be painted over with size and patched with another layer of gold leaf. A small area can be painted over with shell gold. (You may not have stirred your gesso well enough and have a spot that is unable to hold gold or you may have gotten oil from your hands on the gesso.
Uneven surface texture
*Pits and divots can be caused by bubbles in the gesso. Do not use gesso if it has a lot of bubbles. This sounds strange, but mix a little ear wax into the gesso if you have a bubble problem. The ear wax acts sort of like an antacid. Your only other options are wait for the bubbles to settle (if they ever do), or pop them.
*Scratches, gouges and missed bubbles. If they can not be sanded or burnished out, they should be filled in with more gesso, allowed to dry and carefully sanded again before laying gold. If they are missed, you can try to fill the area with more layers of gold.
*Mottled appearance can happen if there is too much honey in the gesso or the gesso was too wet, but some gold stuck anyway. Try laying another layer of leaf over the mottled spot.
*Any number of smudges and spots can occur from burnishing your gold while the gesso underneath is too wet. If you are burnishing and the gold is just rubbing off...stop!!! Put the piece away overnight and try again tomorrow. If the gold continues to rub off, there is another problem.
Cracks in the gold
*Sometimes there are imperfections in the gold itself. Several layers may be needed.
*The gesso may be too soft and the gold cannot stretch enough. Re-apply the gold and don't burnish with as much pressure.
*The gesso may be too brittle. In this case the gesso is what is splitting apart, not the gold. You will usually hear crunching noises and feel the gesso breaking underneath the burnisher. Use a lighter pressure on the burnisher. Try to re-apply the gold over any existing cracks or patch using shell gold
*Sometimes, despite doing everything right, gilding just doesn’t come out as nice as you expected it to. It happens to all of us and it happened to medieval scribes as well. Be prepared for “bad gesso days”.
*Do your gold leafing before you paint and preferably after the calligraphy is done.
* Always do a test piece before applying gesso to a full piece. The same batch of gesso will work differently under different weather conditions. Some days the gesso will work better if you add a bit more honey or slaked plaster.
*Apply size by laying down a small puddle in the middle of the area you wish to gild and pull it into corners and around edges. A smooth, even application of gesso will save a lot of work sanding and burnishing.
*Lay a piece of scrap paper down beside the areas you are sanding. The sandpaper will raise the nap of anything it rubs across. It’s much better to ruin a piece of scrap paper than the scroll you are working on. If you do happen to get gesso dust into the fibers of the paper, an eraser usually removes it without any problems.
*Cut pieces of gold slightly larger than the area you wish to gild. This may seem like a waste, but it’s not. You will waste far more gold trying to match tiny bits together to fill in missed areas than you would if you had just used a little more in the first place.
* Small repairs can be made with tiny bits of gold. It may be a bit tricky to use tweezers. A paint brush rubbed through your hair will produce enought static electricity to attract and hold a small piece of gold long enough for you to place it.
*Save all of the gold scraps you brush off of your work. You can make your own shell gold with them. Mix the gold flakes with some table salt and honey. Grind well with a mortar and pestle. The gold mixture will look a bit like mustard. Add a good bit of distilled water and pour into a clear jar or test tube. When all of the gold has settled, remove most of the water with a dropper. Add more clean water, shake and repeat. Do this several times then taste the water. If it is not salty or sweet, you are done making the gold into pigment. Draw off most of the water and pour the gold sludge into a shell. Mix it with a few drops of gum arabic and let it dry. Store it until you want to use it.
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