27 Jul 21

The 28th Regiment at Quatre Bras (1875) frame treatment

The commanding gilded frame surrounding Elizabeth Thompson’s The 28th Regiment at Quatre Bras (1875) is a simplified trophy frame. This style of frame uses motifs and symbols relevant to the painting it houses to tie the painting to a particular myth, event or family or, as is the case here, military engagements of the 28th (North Gloucestershire) Regiment of Foot. The frame is likely contemporary to the painting dated 1875 and was perhaps even designed by the artist herself when the painting was commissioned by Charles Galloway.

Military style trophy frames commonly depict trophies secured after battle and draw on the historical practice of stockpiling and displaying property, arms and captives captured by the victor in war. These frames relay a parallel story with the painting the public can connect with by looking closely at the symbols and icons represented. Here, the two uppermost corner blocks depict crossed rifles, indicative of an infantry unit, and the lower two blocks depict crossed canons reflecting an artillery unit.

The arched form crowning the frame depicts the Royal Coat of Arms of the United Kingdom with its motto Honi soit qui mal y pense (translated as Shamed be whoever thinks bad of it), flanked with rifles, cannons and spears draped in the English flag. The image of the Sphinx and inscription ‘Egypt’, mark the 28th Regiment’s Egypt campaign (March 8–August 26 1801) and their involvement with the battles at: Aboukir, Roman Camp, Alexandria (March 21), Cairo, Alexandria (August 17–September 2 1801). The arched form also references the triumphal arch of the Roman period which indicated military victory and superiority. It was also a symbolic device used during the nineteenth century by fraternal organisations such as Freemasons, trade unions and friendly societies as a symbol of strength and unity, the protection of God and the fellowship of the brotherhood.

The list of inscribed names across the side and lower member of the frame references the various battle honours held by the 28th (North Gloucester) Regiment of Foot. In the Peninsula War campaign the 28th Regiment were employed in battle at: Corunna, Barrosa, Albuhera, Vittoria, Pyrenees, Nivelle, Nive, Orthes, Toulouse, Peninsula. They were also involved in the Napoleonic War (Waterloo) and Crimea War (Alma, Inkerman, Sevastopol). The laurel leaf motif linking these names is synonymous with Apollo and conquering heroes were commonly crowned with laurel leaves as a symbol of glory and atonement.

Conservation Treatment

Bronze paint

Conservation treatment was undertaken to remove a bronze paint layer that had been applied across the frame.

Bronze paint was commonly applied to gilded surfaces to disguise damage to the surface, such as abrasion. The bronze powders that make up bronze paint are copper-zinc alloys and should be more accurately called brass. The powder consists of tiny flat pieces of metals suspended in a liquid medium. These pigments are two-dimensional and opaque. Once dry they form a tight laminate structure, creating a high lustre through light reflectance.

Initially the colour of the bronze paint is similar to gold, but unlike gold which is a noble metal and does not react and discolour when exposed to air, the powdered metal that makes up bronze paint reacts to air over time. This reaction causes the dulled greenish-brown hue of an aged bronze paint surface, as visible in the mid-treatment images below. In contrast, frame surfaces gilded with gold leaf*Gold or gold alloys beaten to a thickness of approximately 0.1 microns. will never show signs of tarnishing or discolouration. They continue to look as bright as the day they were gilded, decades or even hundreds of years later.

Elizabeth Thompson’s The 28th Regiment at Quarter Bras, 1875, frame during treatment. The left side of the image shows the reflective water gilded surface found beneath the oxidised bronze paint still present on the right hand side of the frame.

The grinding process used to create bronze powders was first developed in the seventeenth century in Germany and was so labour intensive that it was restricted to use on high quality objects. Its commercialisation was later developed by Henry Bessemer making the material more widely accessible and in common use by the mid-nineteenth century.

Overpaint removal

The removal of any coating on a frame, including dust and dirt, could affect the underlying gold leaf. Even water on a damp cloth can cause removal of a gilded surface if it has been water gilded*One of two main types of gilding, where gold leaf is laid onto a prepared surface of gesso and bole. ‘Gilder’s liquor’ (generally water with a small amount of alcohol) is used to reactivate the adhesive in the bole, securing the gold leaf in place. It is more commonly used on flat or gently curved areas of ornament, and can be burnished to a high shine. . The aim of this treatment was to reveal as much of the original surface of the frame as possible whilst reducing the risk of damage to the original gilding, so a structured approach to bronze paint removal was carried out.

Cross-section of the gilded surface viewed under microscope where 400um = 0.4mm. The gold leaf is visible as an unbroken gold line above the pink foundation (bole) with the platelets of oxidised bronze paint sitting stacked on the gold leaf.

To help get a better understanding of the original gilding scheme, samples for cross-sections were taken and solvent spot tests*Testing method used in conservation treatments where very small quantities of solvents are applied to discrete areas on a frame. These tests help determine the type of gilding and the treatment method to be used. carried out across the frame in key locations. The cross-sections were viewed under magnification using both visible and ultraviolet (UV) light to help understand the build-up of the surface layers and to help distinguish between oil and water gilded surfaces. Metallic pigments are suspended in an oil medium*Oil-based paint binder, often based on linseed oil. to help protect the metal particles from air and moisture. Removal of bronze paint requires dissolving the oil medium carrier. If the underlying, original gilded surfaces are oil based, removal of the bronze paint is very difficult as these layers share the same solubility. However, if the underlying layer is water-gilded, a process which uses water-based materials, removal of the bronze overpaint is straight forward as the solubility of the bronze paint oil medium and the water gilded surface are very different. Many frames of this period used a mix of both water and oil gilding*One of two main types of gilding. A drying oil such as linseed oil mixed with metallic dryers is brushed onto a frame to create a slightly tacky surface. The gold leaf is then laid onto this. It commonly applied to decorative or ornate surfaces. Also called mordant gilding. and it is through knowledge of traditional frame production and design, chemical spot testing and analysis that conservators can safely remove these overlying bronze paint layers.

With a better understanding of the order, composition and thickness of each of the layers, a range of solvents were applied to test areas to evaluate their efficacy. In addition to mixing solvents, various methods of applying the solvent were tested to soften and remove the bronze paint. Their success was judged on their working time – one that was not too fast as to be uncontrollable and not too slow as to be inefficient. Solvents were tested in liquid and gel forms and applied as a poultice*An absorbant material, such as fabric or cotton wool, dampened with solvent and applied to a surface in conservation treatments. or covered after application to reduce the evaporation rate.

Areas where the bronze paint had been more thickly applied required scraping back the thick bronze paint with a scalpel to reduce and disturb the overpaint. This general methodology, with slight adjustments to solvent time as required, proved very effective in removing the uneven, oxidised*Deterioration due to chemical reactions involving oxygen. bronze overpaint to reveal the original water gilded surface and its original ormolu*A coating applied to gold leaf to matte the surface, shift the tone or as a protective layer. It is generally made with animal glue and shellac, into which pigments or dyes can be added. surface coating.

Repairing losses to the gilding

Overpainting a gilded surface is commonly done to disguise damage but the extent of this damage is never fully revealed until the overpaint layers are removed. For this reason, the start of the bronze paint removal process is always a journey into the unknown. Fortunately, the damage to the original gold leaf was minor and limited to the torus*A semi-circular decorative moulding, often applied to the top edge of a frame. along the lower member. This is an area that usually gathers dust that is then wiped repeatedly with a cloth, which especially when wet or damp, can abrade or dissolve the very thin water gilded surface.

When restoring areas of loss, conservators look for methods that help to distinguish original from new, that do not alter or affect the original, and can be easily removed from the original if required. This ensures that future researchers can distinguish between ‘old’ and ‘new’ materials and that the frame can be easily re-treated in the future without damage to the original. For this treatment an acrylic mordant*A type of adhesive used to adhere gold leaf and other metals during gilding. was chosen as it has a different solubility to the water gilded frame and could be removed.

The restored areas must also integrate visually with the original gold, so as not to be distracting to the viewer. The colour of the gold leaf is determined by its composition, leaf thickness, the colour of the underlying foundation layers and protective coatings applied over it. Gold leaf commonly contains a small quantity of one or two other metals to create various shades from true 24 karat gold, through to warmer or cooler shades made with the addition of copper or silver and palladium, respectively. This leaf is applied to a bole foundation layer. This is traditionally red earth based (as visible in the cross-section) on water gilded surfaces. As a natural colourant, the red earth clay bole can be quite varied in its tone depending on the quantities of iron oxide, gypsum and calcite found at the source. The original bole on The 28th Regiment at Quatre Bras frame is quite light, leaning toward pink, indicating low iron oxide content.

For this treatment, a 23.5kt gold leaf was applied over the original bole in areas of loss. The acrylic mordant was lightly brushed on the surface, restricted to the areas of gilding loss, and left to completely dry. The gold leaf is then applied after reactivating the acrylic by breathing on it, which provides light moisture and heat to the acrylic layer, making it slightly tacky. The infilled gold leaf was lightly rubbed and distressed to blend in with surrounding original leaf and an acrylic protective coating, tinted to replicate the ormolu, applied.

This conservation treatment involved researching the significance of the frame design and its relationship to the painting, understanding the methods used in its production and the restorations it had undergone, analytical research into solvents and extensive testing before the skilled hands-on treatment even commenced. Now, the surface finish on The 28th Regiment at Quatre Bras frame is an honest appearance of a water gilded frame surface that is almost 150 years old. Though there are areas of light wear and loss to the gilding, and fine cracks associated with movement of the frame structure, each of these imperfections are stories of use and wear and material change to the frame parts over time. It is also a reminder that efforts to restore such surfaces to “new” by broadly overpainting, can in time be detrimental to a frame’s appearance and the presentation of the artwork it houses.

Read more about frames at the NGV’s Centre for Frame Research