As published in ID - Digest Magazine, May 2010
This article is addressed to interior designers or decorators who ask the question, ‘What is water gilding and why should I pay for, or propose that the client pays for this more expensive option compared to other types of gilding?’
The reason to pay more is for the quality, certainly, as it is in most cases when we might agree to extra expense. But this extra quality may not always be necessary. Water gilding is necessary in the restoration of antiques, and can be used to great effect in contemporary decor. In this article I hope to explain how water gilding differs from other gilded finishes and help decorators and designers to make a more informed choice when they choose between them.
Water gilding in a modern context is suitable for high quality, carved or smooth wooden objects that you wish to gild. Carved picture frames and chair frames, furniture, and wooden sculpture are good examples. The gilding, if done well, will last centuries, will not tarnish, will glow with the inimitable lustre of real burnished gold, and will have an inherent value. Water gilding is generally not suitable for quick gilding jobs, a lot of architectural gilding, and outdoor gilding.
Water gilding refers to the process of attaching extremely thin leaves of gold to a prepared surface. It is called water gilding because the surface is wet when the leaf is attached. In reality the gilder is wetting a carefully prepared surface to revive its adhesive qualities and to create a situation where the fine leaf of gold is captured by the surface tension of the water, spread and pulled down to adhere to the surface as the water absorbs into it.
This process is laborious because it involves patient, skilled handling of the gold, which is so thin that it can be blown away with a breath. It also requires a careful preparation of the surface to be gilded, and a good understanding of the materials and processes involved. Although water gilding can be done with ‘false’ gold, (economical metal leaf made with brass and other metals), historically it was always done with real gold or silver leaf.
Water gilding in Italy was practiced and developed in the 13th, 14th and 15th century as a means of decorating wooden objects such as altar panels, mostly for the churches. Although we now see these antique objects in a very tattered state, with the gold leaf worn back to show the overlaps between the leaves and the red ground beneath, that is not how they were originally intended. As the author Daniel V. Thompson puts it his book ‘The Materials and Techniques of Medieval Painting’, we must imagine that we are seeing them as Christmas trees in August, past their prime. We have developed a taste and a love for the look of worn leaf, so much so that many attempts are made to copy this look.
It is important when considering water gilding that we consider the object to be decorated as a whole. The intent of the renaissance craftsmen was to make something precious, often an object of devotion. This way of making the surface seem like a solid sheet of gold was designed for wooden objects, wood being the primary material available to them for this purpose. Water gilding today is practiced in much the same way as it was in the renaissance.
The wood is coated with a mixture of animal glue and chalk called gesso. This mixture, applied as a warm liquid, binds to the surface, fills the pores yet does not seal the surface and therefore allows to a certain extent for the natural expansion and contraction of the wood, according to humidity levels. The gesso can be sanded to a very smooth surface when dry. Bole is then applied to the smooth gesso. Bole is fine clay, commonly yellow ochre or a deep reddish tone, which is mixed with a glue binder. Both the gesso and the bole have the quality that they can be burnished, that is, when they are flattened with pressure applied from a burnishing tool they compress and shine. After the gold leaf is water gilded to the prepared surface, it is allowed to dry and then it is burnished with an agate stone-burnishing tool. It is from the compression of the under lying layers that true water gilding takes its shine.
Other methods of gilding have been developed in more recent times. The most common method of attaching gold leaf to a surface today is with the use of gold size. Gold size is glue that is applied to the surface to be gilded and left until it reaches ‘tack’. When the right tack is reached the leaf can be applied. Depending on the type of gold size used the time to reach tack can vary from 5 minutes to 12 hours. The longer tack times are generally the property of oil sizes and they are preferred for their self-leveling qualities that produce a very smooth gilded surface. They must of course be used in dust free environments to avoid dust settling on the sticky surface during the long setting time. Gold applied with size cannot be burnished and this is perhaps the most important aesthetic difference between water gilding and ‘mordant’ or size gilding.
The skilled gilder can combine methods of mordant and water gilding and advise on which would be best for each particular project. Here are some common undesirable problems that can crop up of when dealing with gilded surfaces and the errors that may have caused them:
Scratches, crevices and brushstrokes can be seen in the shiny surface of the gilded surface
A rough surface under the leaf will show in the finish so special attention must be paid to the preparation of the base
Crinkly or patchy looking gold leaf
This is usually a problem with mordant gilding rather than water gilding. Sometimes the gilder makes the error of applying size badly or attaching the gold leaf either before the size has reached tack, or waits too long. Metal leaf that turns green or oxidizes with time If false leaf is used this is always a risk. It can be delayed with the application of a protective varnish when the leaf is newly applied. Real gold will not tarnish.
Metal leaf which scratches off easily
With some of the hobby type water based mordants the gilded surface created is not durable, even when varnished, therefore this technique is not suitable for use on furniture.
The time-honored tradition of water gilding is truly a beautiful, high quality, long lasting form of decoration. There is much to know about gilding in general and there are many pitfalls to avoid when making technical choices for your gilding project. I hope that this article may be helpful to those who love the glitter of gold and wish to learn more about gilding.
For exquisite examples of contemporary gilding visit the web site of Michele A. Caron of the United States. Michele A. Caron is an American and European trained gilder and conservator with 25 years of experience. Her training and technical procedures are firmly established in the European tradition while at the same time maintaining an open mind towards the contemporary and the future.
Author: Special Feature by Contributing Writer Alison Woolley Florenceart.net Contributing Credits: Contemporary Gilding Michele A. Caron Department: PAINT and PLASTER Gild-Shine-Metallic May 2010 Executive Editor: Judy Arnold ID-DIGEST.COM