The Art of Glass Gilding

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Laying Out the Design
Screen printing an outline is one way to engineer a glass gildingjob. A more common technique is to pounce a pattern on the window.After painting the outline, you can gild the areas inside it.
The next step involves backing up the gold with a mixture of Japanpaint and varnish. Japan paint is used instead of lettering enamelhere because it dries faster. The excess leaf is then washed away.(Note: If you haven't developed the skills of hand-lettering, youcan also cut a paint-mask stencil using a product such as R Tape'sProGrade(TM) paint mask to paint an outline and drop shadows.)
Another common way to layout the job is to apply the gold leafdirectly to the glass. After the gilded area is dry, pounce thedesign over the gold leaf. After backing up the areas with paint,clean off the excess.
Mixing the Size
For surface gilding, sign makers will generally use an oil size. Ingilding glass, a water size is used. Balabuszko recommendspreparing your water size just before gilding. He also says thatyou should only mix the amount that you'll use. Water size doesn'tkeep well, so don't store any of the unused mixture.
For Bob Behounek's Chicago Blackhawks sign, two OO gelatin capsuleswere dissolved in a pint of distilled water. Balabuszko emphasizeskeeping this can clean and using only distilled water to preventany contamination that could cloud the gold.
Heating the water dissolves the water-clear gelatin. Balabuszkodissolves the capsules in a stainless steel can, which he only usesfor this purpose. After the size dissolves, it isn't necessary forthe water to stay warm (but it helps, because the warmer the water,the faster it dries).
Balabuszko recommends avoiding any potential fire hazard by usingan electrical heater. After heating, the size should be strained.Regardless of which heat source you use, you must warm the water todissolve the capsules. Balabuszko cautions not to boil the water.(Boiling can cause the dissolved gelatin to harden as the waterevaporates.)
Capsules aren't the only way to buy gelatin size. It's also sold insheets divided into diamond-shaped pieces. As a rule of thumb,you'll generally use two diamonds for every 00 gelatin capsule.
More isn't always better when mixing up a batch of water size. Inmost cases, you should resist the temptation to add extra gelatincapsules to your mixture. Sure strong mixtures create a strong bondto the glass-sometimes too strong, when it comes time to clean offunwanted gold from the glass. Balabuszko also says that too stronga mixture can become hazy over time, thereby lessening thebrilliance of the mirror finish. Too weak of a mixture of size,though, is worse than too much. A weak mixture can result in thegold leaf chipping and peeling.
Applying the Gold Leaf
After the glass has been cleaned, it's time to apply the size.Whereas oil size used in surface gilding is the consistency ofpaint and is applied only to the area to be gilded, water size is"watery" and is applied to the glass above the area to be gilded.The water size is applied with a special brush (called a flat washbrush or size brush), which allows a steady stream or sheet of sizeto flow or run down the side of the glass.
In applying the size, don't hold back. Liberally brush on the sizeabove the area to be gilded so that it streams down the side of theglass. Balabuszko first floods a coat of size over the entire areaand then reapplies the size to the area that he's working on.
Gilding glass isn't generally affected by the weather becauseapplications are done second surface on the inside of the window.Sub-zero temperatures can be a big problem though. If ice forms onthe inside of the window, there's nothing you can do other thanwait until temperatures rise. "At extremely cold temperatures, thewater size will freeze, and the gold just won't stick," explainsBalabuszko. (Warning: Heating the window with a torch or heat gunwill crack the glass.)
After wetting the glass surface, the next step is to apply the goldleaf. This process requires that you learn how to use a gilder'stip. "The old-timers would brush the gilder's tip against theirhair to pick up some oil," says gilder Eric Elmgren. "The oil onthe hairs of the brush would stick to the gold, so you could puteach piece in its place. Unfortunately I don't have much hairanymore, and what little I have left, I don't use any stuff on it."Elmgren suggests that an alternative way to use this brush is tofirst apply a small amount of brush oil or vaseline intensive careto your arm. Brush the gilder's tip against the oil on your arm andthen touch the gilder's tip against a sheet of gold leaf. The tipwill lift the leaf from the paper so that you can transfer it tothe glass.
In laying sheets of gold leaf in place, Balabuszko comments thatmore right-handed people prefer working from left to right (toavoid leaning against their work). Left-handed gilders, however,should lay the leaf starting from the right and working left.Regardless of the sequence you use in laying leaf, Balabuszkoadvises that you minimize the number of overlapping pieces as bestyou can, so as to minimize any noticeable seams in the gilding.
In applying the leaf, Balabuszko starts at the top of the letterand lays subsequent sheets below the preceding ones. If the goldleaf doesn't lay perfectly flat, blowing on the gold leaf can helpsmooth the sheet. "Watch what you're doing when you apply a secondwash of size," advises Balabusko. "Too much wash and your gold canslide down the glass. Once that happens, it's virtually impossibleto put the leaf back in place.
"If the gold leaf starts to slide out of place, you can sometimesstop the slippage by blowing on it. Touching the leaf with thegilder's tip for a second can also help secure the sheet in place."
Applying a second wash of water size generally will also brightenthe luster of the finish and strengthen the bond of the gold to thewindow. Often when the gold leaf is first applied over the watersize wash, it'll appear satiny through the first surface of theglass. Not to worry: As the size dries, the gold will tighten up,and the finish of the gilding will become glossier. "Don't fretabout any small wrinkles," counsels Balabuszko. "They'reinevitable. Most won't even be noticed when the excess gold isbrushed away and patched."
You won't necessarily want to use full pieces of gold leaf, if asmaller piece will do the trick. Gold leaf can be cut into smallersections. To do this, use a gilder's knife and a gilder's cushion.
After the gold is dry, brush away the excess leaf with a cottonball, powder puff, or mop brush. If you use cotton, be verycareful: It may feel soft, but the fibers are coarse enough toabrade away the gilding from the glass. A squirrel or badger mopbrush may seem to be an expensive tool, but it's a worthwhileinvestment. Because of its softness, it's much safer to use.
Second Gild
After removing the excess gold, inspect your work for holidays(voids in the gilded surface). There are two ways to repair anyholidays: You can either apply more size and gold leaf where it'sneeded, or you can do a second gild. Often Balabuszko will double-gild a glass sign, so the gold is extra-thick.
Performing a second gild produces a high-quality job. Balabuszkocautions, however, that you should make sure you're charging enoughfor the job to cover the additional time and material that'sinvolved.
To give the glass gilding a high-polished finish, some sign makerswill apply a hot wash to the gilding. To do that, dilute the amountof size by 50 percent to make it half strength and then reheat it.Washing the back of the gold with the hot size tightens up thegilding and gives the gilding a mirror finish. "Many gilders don'tadvocate using a hot wash," says Balabuszko. "Some people justdon't like the highly polished surface, because it looks as if thegold has been sprayed on. Others feel that the hot wash potentiallyweakens the adhesion of the gold to the glass."
Balabuszko uses vertical strokes in doing a second gild (applyingthe size directly to the gilded area). "I do a onceover with thesize, and then I leave it alone," he says. "If you overdo it,you'll weaken the gilded area."
Backing Up the Letters
After you've gilded the glass, back up the gold with Japan paint.Smith recommends adding some varnish to the mix. "The higher theconcentration of varnish to paint, the tougher the paint will be,"he explains. (Note: Ratios of Japan paint-to-varnish can varybetween 1:2 to 1:4. After mixing the components together, be sureto strain the mixture to eliminate any paint globs.)
If worse comes to worse, back up the gold leaf with 1-Shot blacklettering enamel. You can improve the flow out of the paint andachieve a nice, shiny finish similar to a lacquer's gloss by addinga paint conditioner (such as Penetrol). Anything that's notprotected with paint is then washed away with a damp brush.
Black isn't the only color that you can use to back-up the gild.Gilders have also used yellow and terracotta red. Each color usedto back up the gold imparts its own tone. "Black makes the goldbold," says Balabuszko. "Yellow makes it mellow, and red gives it arosy appearance."
Make sure that the paint is thoroughly cured before removing theexcess gold. Paints dry faster during warmer summer temperaturesand more slowly when the weather is colder.
After gilding, you can then paint a drop shadow. Remember thatglass gilding is done on the second surface, so you'll have to doeverything in reverse.
Varnishing
After this eradication process, the window graphic should beprotected with a coating of varnish. Balabuszko says that there areall types of varnishes that signmakers use for glass gilding: SparVarnish, Commonwealth Clear, and gloss polyurethanes. "My advice isto try the different products and see what works best," hesuggests. "Once you find a winning combination, continue to useit."
Sign painters protect gold leaf with varnish to provide abrasionresistance and to prevent exposure of the metal from air (which canoxidize the gilded surface). For glass gilding, the coating ofvarnish also protects the size from any moisture that could attackthe size. Remember that water size is water-soluble. Although youcan use most varnishes to protect your work with no problem, somevolatile solvents can attack the size.
Conclusion
For many applications, a gold mirror finish is just what the doctorordered. Gilder Ron Jelinek says that there are a number ofdifferent tricks that you can use to give glass gilding sometexture and some visual interest. "Water size is used, because it'scrystal- clear and produces a brilliant, high-gloss gild," he says."If you're trying to create the illusion of a dimensional letter(such as a chiseled font), you can give one facet of the letter amatte finish and other parts a gloss finish. To give a part of thelettering a matte finish, apply an oil size to those areas. Fastsize is excellent for this application because it dries fast.
"Unlike the water size, an oil size isn't perfectly clear. Watersize produces a mirror finish. The oil size disperses light(creating a matte appearance). Tinting the oil size with a coupleof drops of lettering enamel can also create an interestingeffect."
Jim Hingst Jim Hingst (who also happens to be R Tape's businessdevelopment manager) has over thirty years of quality experience inthe graphic arts market. His career includes a range of activities-including product development, estimating, production planning,vinyl application, and sales and marketing. Jim has contributedmore than 120 articles to many of the leading publications in thesign industry and is also the author of the book Vinyl/SignTechniques. This month, Jim steps away from the vinyl and venturesinto some new territory for himself: the art of gold leaf gildingon glass and windows. These types of exquisite signage areextraordinary, and if you've ever wondered about the tools, skills,and techniques you'll need to accomplish this type of work, turn toJim's "Hingst's Sign Post" column that begins on page 34.