The Building Conservation Directory 2020

INTERIORS 5 155 C AT H E D R A L C O MM U N I C AT I O N S T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 2 0 OIL SIZE GILDING For external applications and large-scale interior decoration the oil size gilding technique is commonly used. This is similar to water gilding but instead of a water- based adhesive, a specially prepared oil size is applied directly to the non-porous substrate. This oil size acts like a contact adhesive: the gilder has to wait until it has all but dried out before applying the gold leaf. This requires great skill gained though experience and lots of trial and error. Unlike water gilding – where you can apply immediately to the wetted surface (indeed, a skilled gilder can sometimes ‘aquaplane’ the gold leaf into position and remove any crinkles), oil gilding is unapologetic. Once you place the gold leaf on the oil size, it is stuck fast. You cannot reposition it and you cannot burnish it to a high shine. POWDERED GOLD PAINT Gold is one of several metals that are sometimes used in paint form, as will be described in the next section. In this case it is genuine gold leaf that’s ground into a powder and suspended in varnish or other viscous liquids to make gold paste or paint. As the medium is translucent, gold paint is generally applied over an orangey-yellow ground, but there is no additional layer of size to worry about or any further burnishing, so the user is free to apply gold in a more immediate fashion. The gold paint technique is thus a much simpler process which can be picked up quite easily by any novice who can wield a brush, so you may wonder why this technique has not replaced gilding with solid gold leaf. However, there is a catch: painting with gold powder gives quite a different aesthetic result. While gilding will create the effect of a solid layer of an undisturbed gold sheet, gold paint will have a sparkly appearance as each particle of gold will be positioned differently to the next one. As the reflective surfaces are not sitting flat and even, the gold will have a slightly ‘rougher’ surface for the light to bounce off, much like eyeshadow. In Europe, real gold was not traditionally used in paint form, and to see it being used more frequently, we must look further afield to Asia where sparkle is a desirable feature when used sparingly, such as in Kintsugi – the Japanese art of deliberately highlighting crack repairs with gold paint. As described by Michelle Mackintosh and Steve Wade in Tokyo (2018, p375); “Kintsugi (‘golden repair’) is the repairing of glass, porcelain… and other forms of pottery with urushi lacquer mixed or dusted with gold (powder)…” This Eastern philosophy of adoration and celebration of the imperfect, known as wabi- sabi in Japan, is an ancient aesthetic which was not favoured in Western decoration. Indeed, the idea of highlighting and celebrating imperfection with a sparkly and powdery stroke of painted gold seems at odds with the West’s fundamental drive for using gold to highlight perfection, with a perfect shiny sheet of gold. Quite possibly this is the reason why gold was not commonly used as a paint in the West. We certainly had the know-how to make gold into paint and were not shy about using high value commodities as powdered paint pigments such as lapis lazuli, a brilliant-blue mineral which was actually more valuable than gold in the middle ages. No doubt the artists and illuminists of medieval Europe must at some point have considered making life a little ‘easier’ for themselves by grinding up the gold leaf and mixing it in to the oil size. It must have been a conscious decision which came simply down to aesthetic intention, spiritual ritual and demand. In this respect the skill needed to gild played a large part in the value of the finished article. There is, however, one famous European decorative technique in which genuine gold powder was used as a paint – Japanning. This was an 18th century version of traditional oriental lacquer work adorning timber or papier-mâché furniture which was made in the West for the Western market. Here, gold is used in paint form to imitate the Eastern aesthetic. FAUX FINISHES AND IMITATION GOLD PAINT Something very interesting happened in the West around the 17th century: faux finishes became popular. If having the genuine article was out of financial reach or impractical, these imitations were the perfect answer, particularly for less wealthy households wanting to emulate the finishes found only in the grandest of households. I say ‘less wealthy’ because it was still hugely expensive and opulent in relative terms to pay an artisan to painstakingly recreate a natural material by hand. However, it was often still a fraction of the cost of having the real thing. Eventually the faux finishes became so popular and the artisans creating them became so good at Detail showing the use of gold paint in Japanning on a Kelmscott Manor cabinet (Photo: Alex Schouvaloff by kind permission of the Society of Antiquaries of London)  WATER GILDING with gold leaf laid on a base of clay and glue and once dried, burnished to a high shine  OIL GILDING with gold leaf laid on a base of ‘size’ (glue) and dusted with a soft brush to remove any lose gold, but not burnished  GOLD-POWDER mixed with a medium, in this case, three-hour gold size: it has come out darker due to the resinous medium. Gilders can also dust the powder on dry but this is only advised on areas of light traffic.  BRONZE POWDER mixed with a medium, in this case ormaline, a clear cellulose liquid: in isolation it is quite a convincing alternative to gold, but alongside genuine gold the differences are clear (Photo: Alexandra Miller)    