Whether you are installing trailer graphics or doing a full wrap of a car or van, surface preparation involves a three-step process of detergent washing, solvent cleaning and a final wipe down with IPA. Read more
Using Paint Mask for Surface Gilding
Paint mask is not just for painted graphics. It’s also great as a stencil for surface gilding. If you have never gilded before, just follow the simple step-by-step process in this story and you can expect professional results.
The above job was produced using a hand-cut paint mask stencil.
Before beginning work, clean the surface. If you are gilding a vehicle, clean the surface just as you would before applying vinyl. See 3-Step Prep for Vehicle Graphics and review the cleaning procedure described. For other surfaces, all you will need to do it wash the substrate with mild detergent and water and then wipe the surface down with isopropyl alcohol.
To facilitate the application of the paint mask, peel back about four to six inches of the release liner exposing the adhesive side of the film. Crease the liner and tack the paint mask in place. Begin squeegeeing, gradually removing the release liner from the paint mask as you apply the film.
You can plotter cut your stencil just as you would plotter cut any other vinyl graphic. Or you can hand cut the design. After prepping the surface, apply the paint mask vinyl to the substrate. If you are hand cutting the pattern, you can layout the design, drawing directly on the paint mask. You can also pounce your pattern directly onto the paint mask as shown in the photo below. Or you can use Saral transfer paper to transfer your design to the paint mask.
After drawing the design on drafting paper or brown kraft paper, perforate the paper using a tool called a pounce wheel. Pouncing on corrugated board prevents dulling of the pounce wheel points.
After perforating the pattern, turn the paper over and lightly sand the surface with 100 grit sandpaper. Sanding will open up the holes.
Using a pounce pad, which is filled with charcoal dust, transfer the design onto the paint mask.
Using an Xacto® knife with a #11 knife blade, cut the paint mask. The RTape ProGrade™ paint mask is a polymeric blend vinyl, which cuts much more easily than cheaper monomeric vinyl paint masks. You only need to apply the slightest of pressure when cutting this film. If you have any difficulty when cutting, change the blade.
After cutting the paint mask, weed the areas which will be gilded.
For really intricate designs, plotter cut the stencils. If you are plotter cutting, you will find that you can cut very fine detail with the ProGrade™ paint mask with no problem.
About Gold Size. Size is the adhesive that a gilder uses to bond either gold leaf or metal leaf material to the substrate. Different formulations of size are available. 12-hour and 3-hour gold size are two types. When you absolutely, positively must get a gold leaf job done the same day as you start, you should use a fast size, such as 1-Shot #4008 Fast Dry Gold Size. Generally, 1 Shot Fast Size sets up in about an hour and has an open time of one to two hours. Open time can vary greatly, so you need to test how fast the size sets up.
Other popular brands of size are LaFranc, Rolco and Luco. Although both water-based and oil-based size is available on the market, oil-based products are typically used for sign applications.
When working with 23-karat gold, I recommend a slow size, such as the Lefranc 12- hour size. For most commercial project the slow size has a number of advantages. When gilding with real gold leaf, using a slow size generally produces a much brighter gild than when using the fast size. The longer window of workability that you have with slow size also allows for those inevitable everyday interruptions.
Size right out of the can have contaminants which can ruin your gold leaf job, especially if you are using the really thin, real 23-karat leaf. Before using it, strain out the congealed globs of dried size, using a paint filter or cheesecloth.
The fast size that we used for our projects was extra chunky variety with plenty of contaminants. Before we started work, we had to strain out the globs.
If you are using the 1-Shot Fast Dry Gold Size and plan to clear coat the job with a urethane clear, you should then add about 5% to 10% of the 1-Shot #4007 Hardener to the size. The hardener will prevent any adverse reaction, such as wrinkling, which can occur between the size and the urethane clear coat. When using a hardener, you should start to monitor the tack of the slow size after ten minutes, because it sets up much faster. Although you would expect the window of workability to be shortened when using hardener, the open time is not necessarily affected.
After straining the size, many sign artists tint it, adding a few drops of imitation gold lettering enamel or a couple of drops of a blue universal paint colorant. You can buy this universal colorant at your local hardware or paint store. If you are gilding on a black or other dark substrate, the addition of the lettering enamel or colorant will give the size some contrast with the background. Otherwise, you may not see where the sizing is on the substrate.
Before painting the sizing, resqueegee the paint mask to ensure that the edges of the vinyl masking are securely in place. That way the size will not bleed underneath the masking, which will result in a ragged edge. Of course, if bleeding occurs, you can always disguise the ragged edges with a pinstripe.
After resqueegeeing the paint mask, the next step is to wipe down the open areas of the design not covered with the mask. Many sign makers will use a tack cloth. An alternative is to wipe the area with a damp cellulose sponge. You can find these sponges at hardware stores. Wiping with a damp sponge accomplishes two results. First, it kills any static. And second, it ensures that the substrate is dust free.
To apply the size, many gilders use a lettering quill. As an alternative, try using a fitch, such as the "The David Hightower Fitch" by the Andrew Mack & Son Brush Company. This white hog bristle fitch has much shorter hair length than their standard fitch brush. With its shorter length, the hairs are stiffer, and consequently do a better job of getting the size into any tight corners, and are better at brushing out any puddling. Many fitch brushes are cupped. That means that looking from the side of the brush that its tip has a rounded shape. The advantage of the cupped tip is that you have better control with the brush; it also allows you to feather the sizing or paint.
Using a stiff brush, such as a “David Hightower” fitch, brush on the gold size.
Before applying the size, pallet your brush just as you would if you were using paint instead. Many gilders use the size straight out of the can, never thinning it. If you thin the size, be very careful. Overthinning can weaken its bonding strength.
For good adhesion of the gold leaf, you only need to apply a light coat of size. Be sure that the sizing doesn’t puddle along the edges of the masking. Use a stiff fitch brush to mop up any excess size that accumulates along the edges and corners of the paint mask. If you get a speck of dust in your size, use the tip of your brush to pick it up and transfer it to the masking outside of your design area.
After applying the size, you can remove the masking. In this removal process, be very careful that the masking does not touch the sizing. The impression that the masking leaves in the size will show up in the gilding.
After the size is applied, carefully remove the paint mask, making sure that you don’t touch any of the size with the masking.
Generally, it will take 40 to 180 minutes, more or less, for fast size to tack up enough to apply the gold leaf. The length of time required for drying can vary greatly depending on ambient temperature and humidity as well as varying from one product to another. Slow size, on the other hand, is ready to gild after about twelve to eighteen hours following application. This window of workability, in which the size is ready for gilding, can extend for weeks. Another advantage is that slow size produces a more durable finished product.
After you apply you size to your work surface, also apply some to a test panel and write down the time the size was applied and the time it should be ready. Timing is everything. If you apply gold leaf too soon, you can drown the leaf in the size, which will dull the brilliance of the gold. If you wait too long and miss the window of opportunity, the gold leaf will not adhere properly and will flake off.
Twenty minutes after applying the fast size, start to check for proper tack. To do this, drag the back of you knuckle against the size. If you knuckle makes a squeaking sound, the sizing is ready for gilding. If the sizing has not sufficiently dried, wait ten minutes and repeat the knuckle test. Keep checking every ten minutes until the size is ready.
When working with gold leaf, cleanliness is next to godliness. Your hands are usually contaminated with oils and sweat, which you easily transfer to the leaf material. Any oil deposited on the leaf can act as an adherent for dirt. Always wash your hands before working with gold leaf. Avoid touching the leaf.
About Gold Leaf and Metal Leaf. Gold leaf is available at some sign supply distributors. A book of gold leaf contains 25 leaves, each of which is 3-3/8” x 3-3/8”. Each book contains enough gold leaf for you to gild approximately two square feet. Separating the leaves of loose gold leaf are sheets of tissue paper. Patent leaf is gold leaf, which is bonded to the tissue paper.
“A major difference between patent leaf and loose leaf is that loose leaf has "rouge dust" on the tissue sheets, which prevents the gold from sticking to the paper. The tissue paper between leaves of patent leaf doesn’t (have rouge dust),” says Dr. Francis Lestingi of Signs of Gold and the Society of Gilders. “Also, patent leaf is always a lighter weight than loose leaf. I like to say that patent is novice-friendly. That doesn’t mean that it’s a substitute for loose leaf. Eventually to do really professional work, you must learn how to gild with loose leaf.”
Gold leaf comes in books of 25 sheets. Thin backing paper separates one loose leaf from another. Pictured here is patent leaf, which is gold leaf material that is stuck to the backing paper.
In most cases you can work faster laying loose leaf, than working with patent leaf. Experienced gilders also believe that you can achieve a more brilliant gild with loose leaf. The reason that patent leaf does not produce as glossy of a finish is that the surface of the gold picks up the impression of the paper. Nevertheless, if you haven’t worked with gold leaf before and you are working in a flat, smooth substrate, patent leaf is much easier for the newbie to work with than loose leaf.
Patent leaf is a gold leaf which has been stuck to a paper backing. The backing aids in the transfer and application of the gold leaf to the size. After the gold leaf has been pressed into the sizing, the paper easily releases form the leaf.
Variegated leaf, which is shown in the picture at the beginning of this article, is a type of metal leaf material, also referred to as composition leaf. Metal leaf can look like real gold, but it isn’t. Instead, it is an alloy or combination of metals, such as brass, copper, aluminum, and zinc. This foil material comes in loose sheets, 5-1/2” x 5-1/2”. Composition leaf is thicker than real 23-karat gold leaf and you can pick it up with your hands. To transfer the gold leaf into the size, you will need to use a special brush, called a gilder’s tip. Avoid using your hands.
Carefully place the sheet of metal leaf over the size. Use a soft brush to press the leaf into the size, taking extra care to work the edges. If you are working with the thicker composition leaf you can also use the heel of you hand to press the leaf material in place. After the sizing has completely dried, the metal leaf is permanently adhered to the substrate.
After the leaf is positioned in place, some gilders will use a cotton ball or a soft mop brush to gently press the leaf into the size and then brush away any of the excess gold. Be very careful when rubbing the gold with the cotton ball. Although the cotton feels soft, the cotton fibers are coarse enough to scratch the soft gold. The more that you rub the gold with the cotton, the less the gold will shine.
Using a soft, natural hair mop brush, brush away the excess metal leaf.
In applying patent leaf, rub the backing of the patent leaf gently until the leaf transfers. Do not let the edges of the backing paper touch the sizing. An error such as this might show up in the burnished gold as a dull spot.
Humid conditions might result in a residue of leaf outside of the design area. Gold leaf residue is also prone to sticking to a freshly painted vehicle, which can outgas for as long as thirty days. During this period the paint can be tacky.
Some sign makers clean up the excess with a clean, lint-free rag dipped in wax and grease remover. Be extremely careful if you do this. If you touch the edge of the gilded area the wax and grease remover, it will dissolve the size. Instead, try washing away the excess leaf with cotton ball soaked in soapy water.
After gold leaf or metal leaf is applied you can outline the design with pinstriping. Before you do any outlining, you may want to clear coat the job. That way, if you make a mistake, you can easily wipe away the lettering enamel with mineral spirits without fear of damaging the gilding. A number of different types of clear coats are used to protect gold leaf, ranging from acrylic top coats to automotive urethanes. Before using any clear coat, test it before using it on a job.