Charlotte Roden, independent stained glass conservator
The ‘Cameo Process’ is an acid-etching technique developed at the turn of the twentieth-century which eliminated the need for glass paint on stained glass windows. Pioneered by the Glasgow artist J. T. Stewart, an employee of Meikle and Sons, it provided a solution to the paint loss issues that had plagued studios in the nineteenth-century. Cameo Process windows also embraced the ethos of the Arts and Crafts movement in stained glass at the time, layering modern glasses which, when permeated by light, celebrate the characteristics of unmodified glass. In essence, the Cameo Process involved the intricate etching of a flashed piece of glass so that only thin lines of flash remained on the glass. The flashed glass was etched to a variety of depths in order to create the effect of paint layers (Figs. 1 & 2). The result is a clear, graphic representation of detail on glass which sets it apart from the indistinct results obtained by other studios working towards the same objective.
William Meikle started as wholesale glass merchants in Glasgow, established in 1838 by William Tait Meikle, and did not diversify into glass staining until 1886 when both of William Tait Meikle’s sons, who had been apprentices in Stephen Adam’s stained glass studio, joined to form Meikle and Sons.1 In Glasgow’s International Exhibition of 1888, Meikle and Sons exhibited work, five leaded panels designed in a Moorish style to complement the architecture of the building, was greatly admired.2 It was the talent of two young designers which developed and promoted Meikle and Sons’ artistic capability in the stained-glass industry. Jonathan C. Carr and John T. Stewart, headhunted by Meikle and Sons from the Decorative Studios of the shipbuilder William Denny and Co., visited Morris and Company studios in London in the summer of 1895.3 There they met Walter Crane, Sir Edward Poynter, Lord Leighton and Edward Burne-Jones and William Morris, who took an especially great interest in their work. They must surely have returned to Glasgow motivated and inspired. The following year Stewart and Carr held a joint exhibition which attracted a great deal of attention, heralding a ‘New Art Movement in Glasgow’ and describing their work as ‘astonishing’ and ‘a revelation’.4 Meikle was also congratulated for awarding such public recognition to his designers and craftsmen, as they were allowed to sign their windows, something that would still be rare in stained glass today. At this point, the firm Meikle and Sons were making a name for itself, not only as an established, traditional craft business, but as pioneers in artistic design and innovation.
The creative, prolific partnership of Carr and Stewart was short-lived, and in March 1898, J. C. Carr joined the metalwork firm of George Wragge and Company in Manchester.5 At this point, Stewart’s son C. E. Stewart was assisting as an apprentice at Meikle and Sons’ studio where they also took on a new assistant and collaborator, J. S. Melville.6 Together they experimented with various methods of protecting their glass painting from decay before developing the Cameo Process: a complex, intricate technique using a combination of acid-etching and plating to portray details on the glass surface which appear painted. But in 1904 Stewart lost another collaborator when J. S. Melville resigned to join Oscar Paterson’s studio, a rival firm, no doubt causing a great deal of animosity. In 1905, Paterson’s studio produced a window in which acid-etched flashed glass to was used to replace glass paint which is very similar to Meikle and Sons’ Cameo Process. Melville worked with Paterson until 1913 when he was recruited by Tiffany Studios in the USA. Melville’s first commission for the Tiffany company on arriving in America was a window executed entirely using the Cameo Process.7 J. T. and C. E. Stewart continued to work for Meikle and Sons developing the Cameo Process until 1907 when they left Meikle and Sons to form their own studio where they continued to use the Cameo Process in their own windows (although they may not have been calling it by this name), shipping their work as far as Canada and South Africa. Meikle and Sons seem to have stopped manufacturing Cameo Process windows after the Stewarts left the company but continued to be one of the largest stained glass companies in Glasgow, glazing both domestic and ecclesial buildings with the unpainted floral motif windows made in the style of Scotland’s Arts and Crafts movement called the Glasgow Style.
Although William Morris had stated that the problem of paint loss was all but solved by the 1880s in the UK, and attributed the blame solely to borax, the threat of paint loss to studios, or indeed clients, was sufficiently serious in Glasgow for Meikle and Sons to develop the Cameo Process as a solution to the problem. The Royal Bavarian Stained Glass Manufactory in Munich was, controversially, commissioned to design and manufacture a unified glazing scheme for Glasgow Cathedral when it was concluded by the re-glazing committee that British stained glass artists were not of a sufficient standard to qualify for a project of this scale and importance.8 The scheme of windows from Munich had been installed between 1859-1864, but within only a few years of installation, the windows were showing significant paint loss. Stephen Adam noted in 1898 that the glass paint had deteriorated due to extreme pollution exacerbated by a damp climate.9 It is logical to assume that Glasgow studios, and certainly their clients, having been given the Munich glass scheme as an example of excellence in stained glass, were sceptical of the durability of glass paint, and could see that devising a means of decorating windows without the need for glass paint could be extremely lucrative. Meikle and Sons were bound to have an economic advantage, having been recommended by architects for the quality and durability of their glass in an architectural journal.10 As noted on the information card accompanying the Meikle and Sons window displayed in St Mungo’s Museum, Glasgow, ‘the Cameo Process was preferred to the more traditional methods of glass painting because it was thought more durable.’ Evidence of minimising the use of glass paint for practical reasons can also be seen in the windows of the Glasgow studio of Stephen Adam & Son, which used elaborate leading to replace painted inscriptions (Fig. 3), similar to that of La Farge in America. The first Cameo Process window made entirely without glass paint was the five-light Queen Victoria memorial window in Bo’ness Old Kirk, Falkirk, manufactured in September 1903 (Fig. 4), which cost £350.11 J. T. Stewart worked with Melville on this ground-breaking window but soon after Melville’s departure to Paterson’s studio, a row was published in The Evening Times where William Meikle defended his company and its artist, J. T. Stewart, as the inventor of the technique, refuting the suggestion that Oscar Paterson had used this technique first.12
Flashed glass was used to achieve the effect of the Cameo Process. Flashed glass is a single sheet of coloured glass which has two layers within the sheet, usually one colour applied to a white (uncoloured) base. For Cameo Process glass, a burgundy flash on white glass was used, which was acid-etched to achieve the design, was often plated with an acid-etched green flash on white glass, sometimes plated with an additional third sheet of coloured glass which was not etched (for example, yellow Fig. 5). To block the action of the hydrofluoric acid in areas where the full flashed colour should remain, a stopping-out agent such as bitumen paint is applied to protect the glass. The bitumen paint can be applied using a variety of methods. Commonly, the bitumen paint is applied with a brush or sponge. In addition to this, the artist must consider the duration the glass is immersed in the hydrofluoric acid. The length of time the glass is left in the hydrofluoric acid significantly alters the colour remaining on the glass. Different glasses will have a different rate of dissolution and therefore a test must be completed on new flashed glass to ensure accuracy of colour depth. Moreover, if the depth of the flashed layer varies across the whole sheet, the hydrofluoric acid will etch the surface with an uneven finish; the flash remaining darker at the thicker parts.13 To plan a Cameo Process piece of glass, the design would have been considered in terms of how many different strengths of colour were required on the piece of glass to depict detail. It is plausible that the areas to be coated with the various layers of bitumen would have been detailed on the cartoon so that the artist could be accurate with the application of the bitumen paint during the process’s various stages. It is likely that in its manufacture of Cameo Process glass the studio used the same type of burgundy flashed glass each time, so that they were familiar with its properties. They would have sought a glass with a uniform flash and continued to use this glass as they knew how the glass would etch and how long it would take.14
As the dark flash on the glass was used as the substitute for glass paint, the first step was to paint bitumen to protect the dark flash where the darkest contour lines were to remain. Once the bitumen was dry, the piece of glass was then submerged in hydrofluoric acid to etch the entire glass surface which had not been protected with bitumen. The duration of the submersion had to be monitored carefully and while immersed, the glass would be brushed gently to remove any sediment so that a smooth, even etch could be achieved.14 Once the glass was removed from the hydrofluoric acid and rinsed, more bitumen paint was brushed on to protect the remaining layer of flash, to represent a shaded area of the glass design. This process was repeated until the various depths of shading were achieved and little or no flash remained on the glass (Fig. 6).15 As the flashed layer became thinner, the emersion time in the hydrofluoric acid would be monitored even more carefully; just a few seconds too long and the hydrofluoric acid would remove all flashed colour. To finish, it is possible that a high concentration of hydrofluoric acid was applied with a brush for a delicate, subtle highlight with a nuanced finish.14 The manipulation of the flashed layer was accomplished with such a clear, distinct effect that even at close quarters, it is difficult to distinguish Cameo Process glass from painted glass. The etched piece of glass was then layered with a coloured piece of glass to obtain the desired overall colour when the pieces of glass were stacked. Often, the flashed burgundy etched glass was layered with a yellowish-green tinted glass, so that the etched detail appeared dark brown once the pieces of glass were stacked – similar to the colour of glass paint. Undoubtedly, this intricate process would require a few attempts for each piece of glass on the cartoon, with the artist choosing the best at the end.14 In comparison to the process of glass painting, this complex, time-consuming, dangerous and costly technique gives an insight to the nature of stained glass studios in Glasgow at the turn of the twentieth-century. The studios were driven by intense competition and professional one-upmanship, but I believe that the artists/ craftsmen were absorbed in refining and perfecting their technique; pushing the boundary to what they could achieve.
Michael Donnelly asserts that abrasion was also used as part of this technique but evidence of this could not be found, neither by me nor by other conservators.16 This is an intriguing prospect, of which evidence may be found in the future, which would demonstrate the foundational experimentations of the Cameo Process. The Cameo Process continued to develop after the first entire window was completed. In comparing the acid-etched faces in the Ascension window in Bo’ness Old Kirk, 1903 (Fig. 7) with a head from New Laigh Parish Church, Kilmarnock, circa 1905-06 (Fig. 8) the difference is evident. The first window had two separate pieces of glass etched differently to achieve contour and shading, then stacked within the lead matrix. By 1905, the windows show a more complex process where the various levels of etching are achieved on a single piece of glass (as described above). The first method would indeed have less scope for error and wastage but the second method is the most impressive, involving a huge amount of time and skill. The second method, using less plating, would also reduce the weight of the panels significantly.
In Cameo Process windows, the artist has often chosen to use several modern glasses such as streaky, opalescent and undulating Venetian glass to depict the sky, drapery and natural elements within the windows. These modern glasses add three-dimensionality and celebrate the various effects glass can produce. The densely streaked glasses and opalescent glasses were not layered. Only the lightly streaked glass was layered with Cameo Process glass. In the case of faces and hands, Cameo Process glass was only layered with a plain tinted glass to affect the perceived overall colour. Various glass types and textures were chosen to add to the true likeness of a window, for example, streaky glasses were used to denote fabric folds in the design, glass with an undulating surface depicted cloth movement (fig. 9), or a grainy, uneven glass was used to represent bread (fig. 10). This practice was expertly executed in the Meikle and Sons studio and was a costly design feature as the right streaks must be used in the right place to achieve the effect, which inevitably resulted in much wastage.
A face from ‘The Boy with the Five Loaves and the Two Fishes’ serves as an excellent illustration of the various acid-etched layers in Cameo Process glass. The flashed glass is brown-burgundy on white, and there are at least five layers of etching on the surface of the glass. Therefore, there were five separate immersions in the hydrofluoric acid until the flash had been removed entirely (Fig. 11). As well as multiple etched layers, the colour and depth of shade achieved within the window could also be manipulated by the use of silver stain. Silver stain was used to colour hair, alter the colour of the irises of the eyes, accentuate contour lines and manipulate the hue of opalescent glass. Different coloured plates of glass were used to manipulate the overall effect of the glass, to render perspective and to emphasise the principal figure in the scene. Glass could be acid-etched using the Cameo Process to depict contours and shading, then layered with other coloured glass to gain the desired tone. This can be seen particularly well in ‘The Boy with the Five Loaves and the Two Fishes’ when comparing the colour of the boy to the hands of Saint Andrew and to the hands and face of an Apostle in the background (Fig. 12).
Another very striking aspect of a Cameo Process window is the characteristics of the leading; both the width and the height of the lead cames vary greatly. The interior side, due to the layering of glass within the lead matrix, is extremely uneven where tall leads have been used to accommodate multiple layers of glass. There may also be areas which required only one piece of glass and so here the leads stand tall from the glass surface (Fig. 13). In contrast to this, the exterior surface appears similar to standard-construction, non-layered stained glass where the lead and glass lie flush with each. This happened primarily because of the way a stained glass window is built, but the benefit of the flush exterior surface is that there are less ridges on the exterior to accumulate dirt and debris.
Windows produced by Meikle and Sons using the Cameo Process are rare. As discussed, these windows also contain Arts and Crafts style streaky and textured glass which celebrate the characteristics of the glass, adding a depth of colour and glistening movement to the windows. This was not always the case with Meikle and Sons windows manufactured at the same time and containing standard coloured glass which has been painted. The windows which contained Cameo Process and Arts and Crafts glass seem to have been the ‘premium range’ offered by the company. With these windows, Meikle and Sons were joining the other stained glass artists of the Arts and Crafts movement who were fascinated with the properties of glass itself and wished to utilise the natural imperfections within it to create windows that not only had unquestionable individuality but also had movement and sculptural elements.17 The movement to minimise the use of glass paint in stained glass marked the movement away from a pictorial style of stained glass window, paving the way for lighter, brighter possibilities more suitable for buildings under northern skies.
Many stained glass artists in this period were aiming to minimise glass paint in their work for aesthetic reasons. All surface applications serve to obstruct light and mask the inherent character of glass and it was the properties and effects of glass itself that was inspiring the new artists, therefore surface applications – paints and enamels – were minimised if not eliminated. In addition to minimising glass paint, studios across the world were experimenting with emerging new technologies to develop innovative ways of adding detail to glass. In the UK, many artists such as Christopher Whall, Harry Clarke, Karl Parsons, Leonard Walker and Douglas Strachan were using acid-etching. In Europe, ‘Luce Floreo’ was developed where acid-etched flashed glass in primary colours was layered to create tertiary colours within one piece of glass without the use of vitreous paint (Fig. 14).18 Up to seven layers of flashed glass were etched, either partially or entirely, and superimposed for the desired nuance of colour, depending on the thickness of the remaining flashed colour.19 Antoni Gaudí, dissatisfied with enamels, also used a similar technique in the Capella Reial in the Palma Cathedral, Mallorca, where the combination of etched flashed glasses was used for faces, hands and garments. A sample panel proves that Gaudí also planned to use the trichromy technique for his unfinished Basilica de Sagrada Familia in Barcelona.19 Oscar Paterson (1863–1934), a rival of Meikle and Sons, ‘eclipsed [the larger Glasgow studios – including Meikle and Sons – in terms of publicity and critical acclaim’ and was inspired to challenge tradition in his windows.20 Alf Webster (1883-1915), also from Glasgow, showed expressive potential in his windows around the Glasgow area demonstrating his virtuoso acid-etching and his interest in minimising the use of glass paint. In America, artists were experimenting extensively with plating. John La Farge’s (1835–1910) first stained glass commission was a collaboration with Scottish born Donald MacDonald, an artist keen on experimenting with plating, flashed glass and various textured glasses, where the window was not painted and “very much plated” but was cancelled due to its exorbitant cost.21 Louis Comfort Tiffany (1848–1933) experimented greatly with eliminating glass paint in his windows. He invented various types of textured and sculptural glasses such as confetti, drapery, feather, ripple, spotted, streaky, to depict man-made and natural forms within his windows.22 He experimented with a trichromy technique similar to ‘Luce Floreo’ for St Michael’s Church in New York, and also attempted to replace glass paint by creating metal overlays on glass to depict facial contours. The overlay was a matrix attached to the surrounding lead, which was successful in depicting the intended details but ‘does so at the expense of any subtlety of shading or depth of expression.’23 In Tiffany’s later work, he acid-etched inscriptions and lilies. So when he recruited J. S. Melville (of Meikle and Sons) from Glasgow in 1913, was this in continuation of his pursuit of a technique to rid his windows entirely of glass paint, something which Meikle and Sons had managed to achieve in 1903?24 The Cameo Process is distinct from the acid-etching done in other studios to replace painted details; the distinct, graphic quality of the etched features surpasses the attempts of John La Farge and Tiffany Studios in the USA where the results can appear hazy and obscure (Fig. 15).
The ‘Cameo Process’ is historically significant, in part as a reaction to the late nineteenth-century environment, and in part as an aspect of the Arts and Crafts movement. Above all, its significance lies in the astonishing technical achievements of the craftsmen working for Meikle, whose skills in in acid-etching produce this incredible effect, which has never been surpassed. The painterly effect of the remaining flashed glass is defined, yet often appears feathery like brushstrokes, as though layers of glass paint have been used to build up the contours of the face. Combined with the layering of various colours of glass within the lead came to achieve the desired texture and colour, the Cameo Process had the potential to completely replace glass paint within a stained glass window, albeit at a very high cost. This technique was a highly dangerous and time-consuming process which, although achieving astounding results beyond the capability of the other highly-regarded, contemporary stained glass artists with similar goals, only thrived for a very short period of time. In Scotland, we have lost a number of windows containing the Cameo Process due to the demolition of many churches in the second half of the twentieth-century. Michael Donnelly, while curator at the People’s Palace Museum in Glasgow, saved many windows from destruction. They are now either in storage as part of the People’s Palace collection, or are displayed in St Mungo Museum of Religious Life and Art in Glasgow. Closure is a current issue for church buildings in Scotland and the loss or re-homing of historic stained glass is still a problem.
Further research on the links between Scotland and America in terms of stained glass artists specialised in acid-etching would be very valuable, as would further research on the windows shipped abroad by J. T. and C. E. Stewart.
- Angela Goedicke and Margaret Washbourn, Stained glass marks and monograms. London, 2002; Rona Moody, ‘200 Scottish Stained Glass Artists’, Journal of Stained Glass: Scotland Issue, XXX (2006), p. 181.
- Wyman and Sons, Wyman’s Commerical Encyclopedia of Leading Manufacturers of Great Britain, and Their Productions. Montana USA, 2010.
- Michael Donnelly, Glasgow Stained Glass: A Preliminary Study. Glasgow, 1981; Quiz, ‘New Art Movement in Glasgow’ 10 Dec 10, 1896, pp. 302.
- Quiz, ‘New Art Movement in Glasgow’, 10 December, 1896, pp.302-303.
- Donnelly, Glasgow Stained Glass, 24.
- Michael Donnelly, Scotland’s Stained Glass: Making the Colours Sing. Edinburgh, 1997, p 55.
- Donnelly, Scotland’s Stained Glass, 71; Lindsy R. Parrott of The Neustadt Collection of Tiffany Glass suggests that the first commission of J. S. Melville on arrival at Tiffany may have been The Bathers, lost during the 1957 fire in Laurelton Hall. It was made around 1914 and period articles talk about how paint was not used on the figures. Lindsy R. Parrott, correspondence with the author, 2016.
- Donnelly, Glasgow Stained Glass, 6; Richard Fawcett, Glasgow’s Great Glass Experiment. Edinburgh 2003, p.11.
- Stephen Adam, ‘The Stained Glass Windows’, in The Book of Glasgow Cathedral :A History and Description, ed. George Eyre-Todd, Glasgow,1898, p. 400 and J. W. MacKail, The Life of William Morris, London 1922, volume 2, p. 59.
- Building Industries, 15 Sept 1903, 83.
- Evening Times, ‘Glass Staining’, 27 Nov 1905, p.4; The Scotsman, ‘Queen Victoria Memorial at Bo’ness’ 13 December 1902, p. 11.
- Evening Times, ‘Glass Staining’, 23 Nov 1905, p. 5; Evening Times, ‘Glass Staining’, 27 Nov 1905, p.4.
- Stephen Malcolm, Stephen, Managing Director of Rainbow Glass Studios Ltd. Interview conducted by C. Roden. August 2016.
- S. Malcolm, Interview, August 2016.
- Moira Malcolm, Director of Rainbow Glass Studios Ltd. Interview conducted by C. Roden. August 2016; This is standard practice in acid-etching as described by C. W. Whall in Stained Glass Work (1905, p. 130) where Whall recommends a substance called ‘Brunswick Black’ thinned with turpentine as a stopping agent. Patrick Reyntiens also described this technique and uses beeswax, paraffin wax, sheep tallow or bitumen paint as a stopping-out agent (The Techniques of Stained Glass, London 1977, p. 84) where he also discusses the advantages and disadvantages of all materials. A. L. Duthie (Decorative Glass Processes, London1908) also recommends Brunswick Black as a resist with red lead added for increasing its resisting power.
- Donnelly, Scotland’s Stained Glass, 55.
- Parrott. ‘Unimaginable Splendours’, 89.
- Ulf-Dietrich Korn, ‘Glasmalerei-Restaurierungen in Westfalen 1974-2001. Eine Nachlese,’ in Westfalen – Hefte für Geschichte, Kunst und Volkskunde. Mitteilungen des Vereins für Geschichte und Altertumskunde Westfalens, des LWL-Landesmuseums für Kunst und Kulturgeschichte, des LWL-Amts für Denkmalpflege in Westfalen und des LWL-Museums für Archäologie 81, Lüdenscheid, 2007, p. 416, quoted in Sören Siebe, Rainer Drewello and Markus Kleine,’Luce Floreo: An Historic technique for creating glass windows’ in Recent advances in glass, stained-glass, and ceramics conservation, ICOM-CC Glass and Ceramics Working Group interim meeting and Forum of the International Scientific Committee for the Conservation of Stained Glass(Corpus Vitrearum-ICOMOS) edited by Hannelore Römich and Kate van Lookeren Campagne, Zwolle, 2013, 141-148’; Ulf-Dietrich Korn, ‘Zwei Felder mit Bordüren aus Kiefern- und Stechpalmenzweigen nach 1901’, in Glasmalerei des 19. Jahrhunderts in Deutschland, ed. Monika Böning, Leipzig, 1993, p. 226.
- Korn, Zwei Felder’, 226.
- Donnelly, Scotland’s Stained Glass, 68; Peter Cormack, Arts and Crafts Stained Glass. New Haven and London, 2015, p.133.
- Lance Kasparian, ‘Early Application of “plating” in 19th century American Stained Glass,’ in Techniques du Vitrail au XIXe siècle, Actes du 5ème Forum International pour la Conservation et la Restauration des vitraux, Corpus Vitrearum, edited by Freddy Joris, Namur, 2007, pp. 70-73; John La Farge, The American Art of Glass, New York 1893, p. 13.
- Lindsy R. Parrott, ‘Unimaginable Splendours of Colour: Tiffany’s Opalescent Glass,’ in Louis C. Tiffany and the Art of Devotion, edited by Patricia C. Pongracz,. London 2012, pp.86-113.
- Parrott, ‘Unimaginable Splendours’, 91.
- Michael Donnelly maintains that Tiffany employed Melville in 1913, however, I have been unable to substantiate this assertion with any reference. Donnelly, Scotland’s Stained Glass, p.71.