Copper Horse

One of my favourite metals to work with, apart from gold-leaf, is copper. This is a great metal to start learning to gild with as it is inexpensive to buy. It can be handled easily and does not require any special tools. The copper comes in larger sheets than goldleaf (copper is 12 cm square while gold is 8cm square and is also a lot thicker than the gold leaf, enabling it to be picked up and placed upon the surface by hand instead of using tips and brushes.

For this exercise, you will need the following equipment:

In this demonstration, I am going to gild a carved wooden horse head that I've picked up at TK Maxx (one of my favourite places to pick up samples to work on). I am going to gild it with pure copper leaf, and then make the copper look old by creating the green crust that's found on aged copper, known as 'verdigris'.

A lot of artists will gild an item and then use paints over the surface to give the impression of verdigris, but I am not of that school. I believe that it is much better and a lot more authentic to create the actual verdigris itself, rather than the illusion. That being said, don't be put off! It is not a complex thing to do, and as you will see, it can be achieved with the minimum of fuss and materials.

The horse head has been pre-painted in a green paint that is very close to the look of verdi-gris. If there are any misses with the copper leaf application, it will be unnoticeable with this colour, as it will blend in with the verdigris later.You can of course gild practically anything you like in the same manner as this head, so use your imagination. Plant pots, furniture, old statues, anything can be covered.

I am applying an oil-based size in this instance. I am using a 3-hour size, which is the size I use most. This will mean that the gold will need to be applied within 3 hours. Because of the thickness of the leaf, I shall apply it when the size is a lot tackier than for the gold. This is between two and two and a half hours after application. Today is also a warm day, meaning the size will dry faster as well. Understanding working conditions and temperature will come with time.

For the size application, I am using a standard 1-inch nylon paintbrush. The size is evenly applied over all the surface I wish to coat in copper. The project is a reasonably small one, with regard to the larger leaf size, so I shall apply all the leaf in one sitting instead of staggering different areas.

The leaf is being applied directly from the book. The sheets are 14 cm squared. I start this by placing leaves over the whole of the surface to be gilded, ensuring that there are no gaps. Although many of the leaves are overlapping, I am not going to worry about waste. The copper is inexpensive and by being generous with its application, the overall finish will be better. Once the whole piece is thoroughly covered, I press the copper into place using my fingers.

This piece is being distressed, so I am not overly worried about fingerprints. In other cases, when the finish is not going to be distressed and a clean look is desired, you will need to use a good quality soft brush to tamp down the leaf, such as a 'badgers hair' gilding mop. Care must be taken not to let the brushes touch the size, as it will contaminate the surface and prevent the leaf from sticking very well. Some people use cotton wool, but I have had experience in the past of some of the fibres geting caught up in the oil size on the surface and making a mess, so I would not recommend this.

Now the loose flakes of copper (loose flakes are called 'skewings') are lightly brushed off with the badger hair mop. If you don't yet have a mop, a good quality makeup brush will serve the same purpose until you do. Any missed areas have a little copper leaf pressed into them, to ensure complete cover. There are some incised lines in the horse head surface, which the gold leaf is also pressed into, to ensure cover. There are also many visible lines where the leaf overlaps and joins on the surface. For this project, I am desiring these lines, as they will help to tarnish the head at its completion.

Care must be taken not to over brush the surface, or the agitation could cause the leaf to scratch or tear. If the size is not set enough before application, the copper can easily be removed from the surface, so exercise caution. If any repairs of patches or misses need to be repaired, allow the piece to dry for a day and then re-gild these localised areas using clean size and an artist’s brush. The size should just cover the area for repair, and the leaf should be enough to cover over the size. Once all the flakes are brushed off, the copper head is finished!

The lustre of the copper has a beautiful depth to it that just cannot be replicated with paints. This finish can be left in its own right of course, but if the colour is wanted to remain, it must be treated with a coating of varnish, cellulose lacquer or shellac to prevent it from oxidising or darkening naturally in the atmosphere. For this piece, however, I desire to give it an ancient patina. After allowing the piece to dry thoroughly over a few days, I coat the piece in a generic household bleach. The bleach is applied using a standard 1-inch paintbrush again. It should be rubbed it into the surface in a ragged fashion and not brushed on. If you brush it on, you may get brush lines.

The paintbrush is quite stiff and will give the copper very light scratch marks when it's applying the bleach, but this is good because the bleach has a chance to eat away at the copper at these points. Where the leaves have joins and creases from the application process the bleach will also react in an interesting way. After around 4 hours, Verdigris is clearly visible on the surface. The copper will continue to deepen in Verdigris over the coming day/s, developing antiquity and style. Once a desired finish is obtained, the work can be sealed using a spray lacquer. Do not use a brush to apply any varnish etc, as you will wash off the verdigris. I like to use 'Rustoleum' cellulose lacquer, which is available through quality gilding merchants.

Other household items can also be used to tarnish copper and produce different finishes, including tomato feed fertilizer, hard boiled eggs and ammonia. Why don’t you do a large panel with separate squares and experiment with these finishes...

So, now you have seen the basic skills, you can develop these into bigger and bolder projects. The following frame was gilded in exactly the same way as you’ve been shown.

I purchased a large beaten up frame and re-mitred the corner to fit the canvas painting, an oil paint copy of 'Van Goghs Sunflowers' that I purchased in a Hong Kong market. I oil gilded it in copper using the 3-hour size and applied the bleach. The inset line in the middle has been oil-gilded in 23.5 karat gold on a 3-hour size. The bleach does not affect the gold in any way at all. I have not sealed the piece, as I want it to look natural. This effect is after 7 days and I do not expect it to age much more.