Lisa Cumming and Vicki Hanley, National Museums Scotland

Introduction

From March to June 2012 an exhibition of Scottish railway art entitled See Scotland by Train was held at the National Museum of Scotland (NMS), Edinburgh. It predominantly showcased original posters, as well as oil paintings, photographs and artefacts to complement and highlight the story of railway art in Scotland from the turn of the 20^th century until the present day. Leading artists of the time, such as Frank Brangwyn, Terence Cuneo and Henry Gawthorn were commissioned by railway companies to create these evocative and nostalgic images, and collectively they created a beautiful and extremely popular exhibition.

This article focuses on the management of this exhibition by a small conservation team; from planning to budget issues, materials to design, but in particular, the method of conservation and display adopted for the majority of the posters.

Planning and Decision Making

With an already heavy exhibition and loan work programme, the museum moved the exhibition date forward by three months and cut the budget by 50%. The paper conservation team was now left with 4 months to conserve and mount 25 large works of art on paper, the largest being 3000x2000mm in size.

For assessment and treatment, we divided the posters into two categories: the modern posters and photographs, dating from the 1990s to the present day, which required minimal conservation, and older posters dating from c.1910 to 1960s which required more interventive conservation treatment. The exhibition was supplemented by a loan of eight posters from the National Railway Museum in York (NRM).

Modern Posters

In general, these 13 posters, made from medium weight, machine-made, smooth-surfaced paper, were in reasonable condition, other than light surface dirt on the verso, localised indentations and ‘bruising’ caused by handling and from being stored rolled. The media, although undamaged, was of poor quality, having been cheaply printed for the mass market. The posters were approximately 1015x635mm, or ‘Double Royal’, in size.

The printing inks were sensitive to moisture and were fugitive to rubbing, so a minimal conservation approach was adopted. The versos were surface-cleaned with a chemical sponge and the posters were then pressed without humidification between Bondina® and blotting paper under glass weights, for many weeks until their rolled “memory” had subsided.

Older Posters

Originally made for mass production, these stunning lithographic colour posters were made from machine-made wood-pulp papers of varying quality. They ranged in size from approximately 1520x1000mm (Double Quad) to 1000x1275mm (Quad Royal) and 1015x635mm (Double Royal).

Condition

The lithographic inks were in good condition, having retained excellent colour rendition. The inherent condition of the supporting substrate, however, was poor, with extensive structural damage. Most had been previously folded and all had tears and losses. See Fig.1. One or two posters had rusty tack holes from their past display on wooden boards in railway stations. To add to our problems, prior to acquisition by NMS most of the posters had been commercially treated in preparation for sale at auction, and had received secondary thick, machine-made paper backings, with tertiary heavyweight canvas supports. Both paper and canvas supports had been applied with thick quantities of unknown aqueous adhesive. Losses and tears had been heavily retouched with a plethora of non-archival media such as acrylic, fibre-tipped pen, chalk, watercolour and household paint. The posters without added supports exhibited localised repairs with pressure sensitive tapes. All had then been tightly rolled in plastic telescopic tubes and stored.

This tight rolling of the posters meant that they had to be carefully unrolled and weighted as flat as possible for many days before we were fully able to access them. They retained strong undulations however, with many areas of the primary and secondary supports detaching from one another. These detached areas gave a clearer indication of their extreme fragility. We therefore saw no alternative other than to remove the canvas and paper backings and carry out a full conservation treatment of each poster.

Removal of secondary and tertiary supports.

The lithographic media was first tested for solubility in filtered water, and as anticipated, proved stable. Retouchings were removed using damp cotton wool swabs, erasers or, where no backings existed, the vacuum suction table.

The canvas backing on each poster was removed first. Starting with a loosened corner, the canvas was pulled back at a shallow angle. Although the canvas had provided support for the rolled objects, it was adhered to the paper unevenly with many air bubbles and areas of local delamination. Removal of some of these backings and linings proved tougher than expected and our strength was tested!

The white paper secondary supports were removed aqueously on all but one of the posters. The posters were initially spray humidified, wetting the white paper through quickly and evenly. The posters, supported on Melinex®, were then lowered into a bath of filtered tap water. As soon as the adhesive and secondary support showed signs of softening, the object was lifted on the Melinex® from the bath and turned face down onto another sheet of Melinex® for removal of the white paper. The paper peeled away with ease and the quantity of adhesive left on the poster was evident. See Fig.2. The primary support showed no ill effects from this process, so it was returned face down to a clean bath of warm water for adhesive removal from the verso. Subsequent baths aided the removal of the paste plus soluble discolouration and acidity from the support. The sink was gently tilted to rinse the paste residues away during cleaning whilst moving the water over the verso of the poster.

We were fortunate enough to have use of a large textile wash table, measuring approximately 3140x1510mm. This equipment allowed for the use of temperature-regulated, filtered or de-ionised water, plus tilting to aid drainage.

Handling of the large and damaged posters was awkward, so a large wooden frame with a screen of Reemay® (a non-woven polyester) attached was constructed, on which the larger posters could be washed. See Fig.3. Not only were we able to use it to lift the posters in and out of the bath, but we could also leave the objects could to dry on it, avoiding unnecessary movement. Without the secondary support, the posters were extremely fragile when wet. After washing, the posters’ supports and media were noticeably improved.

Drying

We tested many methods of drying the posters. The most straightforward and successful proved to be “sandwiching” the object between Reemay® and pressing felt. The Reemay® did not cling to the object and the felt absorbed the moisture in a controlled manner, leaving a dried poster with a lustrous quality  and minimal cockling.

Lining

Due to the posters’ inherently weak state, they were lined with Japanese tissue paper to add support and to facilitate repairs and retouching. Because of the large quantity of lining paper required, we purchased a roll of machine-made Japanese tissue that was sympathetic in weight and colour to the objects. The lining paper was cut to size, allowing for a large margin around each edge to assist with stretching out and mounting. Due to their size, most objects required two sheets of lining paper which were positioned onto the verso of the object with a few millimetres’ overlap.

The poster was first wetted out by immersion in water, face down on a sheet of Melinex®. It was then lifted out and excess moisture blotted off. The Japanese lining paper was pasted out with a very thin consistency wheat starch paste and brushed onto the verso of the object. Once lined, the object was transferred face up to dry between Reemay® and pressing felt.

Stretching Out

Following drying, the posters were lightly humidified with a dahlia spray and stretched out either on wooden boards, using gummed paper tape attached to the Japanese tissue margins or, where size permitted, onto the Karibari board. See Fig.4. Some posters with heavier ink needed a second stretching. Whilst flat, they underwent repairs and retouching, which was carried out using dry watercolour pigment, Stabilo® CarbOthello pencils with, where necessary, a methyl cellulose barrier.

Display

A team decision was made to flush-mount the posters onto board in a manner more in keeping with their original method of display in railway stations and on platforms.

White Foamex, an inert, smooth-surfaced, rigid, lightweight PVC board, was chosen. At 12mm thick, it offered a reduced degree of flexing, and a support frame was built on to the back to help improve rigidity, including split battens for attachment to the gallery wall. See Fig.5. Sharp edges and corners were sanded and we attached Tyvek® tape around the edges for added cushioning. Each board was dimensionally larger than its object by 4mm on each side. This display method minimised handling during installation and hid fixings.

The posters were attached to the Foamex under very slight tension but with enough ‘give’ to accommodate any environmental changes – too much tension and there would be a risk of tearing if conditions became too dry. The posters were very lightly sprayed and positioned face up on the Foamex, which was elevated on blocks to facilitate access the underside. See Fig.6. The edges of the lining paper were wrapped around and adhered to the verso of the Foamex board, first with double-sided tape and then with Tyvek® tape to cover the edges of the lining paper. Due to the time constraints at this stage of the project, two posters were not attached to the board under light humidification but were merely positioned in place and attached like the others. During display, all exhibited slight movement during environmental changes but remained remarkably stable overall.

Due to the tight timescale the more modern posters were only framed and glazed, a compromise we made in order to allow us more time for the more damaged historic posters.

Coronation Scot

Our greatest conservation challenge by far was to complete the conservation and mounting of a 3000x2000mm lithographic poster entitled Coronation Scot from 1938, by the artist Bryan De Grineau (1882-1957). Depicting the Coronation and Coronation Scot locomotives, this was the only known example in existence.

We received this poster tightly rolled in four sections, each with a canvas and paper backing as with the other posters. The poster displayed similar structural problems and was inherently brittle. Once it was sufficiently weighted and relaxed from its rolled state, we set about removal of the backings. The canvas was removed in the same manner as the other posters. As each section was so large and weak, we had concerns about how the primary and secondary supports would react with immersion in a bath, and we therefore decided to remove the backing ‘dry’, with scalpels and swabs. This process was extremely time-consuming, and so we enlisted the help of our Textile Conservation colleagues, plus some assistance from colleagues in the Paper Conservation team at National Galleries of Scotland.

Washing in the large bath followed as with the other posters. Soluble dirt, discolouration and adhesive residues were removed, the process being repeated 3-4 times with satisfactory results. Each section was then lined with the same Japanese tissue and wheat starch paste and then stretched out onto boards.

Deciding on a method of display for such a large poster presented other hurdles. If we assembled it whole in our first-floor labs, it would be too large to manoeuvre out of the building, so we set up in the larger Engineering Conservation building to re-unite the four sections.

Support options included Hexlite® honeycomb panel and Foamex, but both would have been heavy and made of multiple sections. We opted instead for a wooden lattice frame, made by NMS Exhibition Technicians, which was dimensionally just greater than the four sections of the poster combined. We first applied a barrier layer of PVA adhesive and then adhered 4 layers of Japanese paper over the entire frame in strips and sheets using a thick-consistency wheat starch paste. See Fig.7. We allowed each layer to dry before proceeding with the next and, by the end, we had a smooth, well-tensioned support, similar to a karibari board, onto which to attach the Coronation Scot poster. On the back, we adhered a heavyweight European paper to pull the lattice frame back into plane. The looming deadline allowed us less than two weeks to construct this ‘lattice’ and attach the object. In ideal circumstances the lattice would have had more Japanese paper layers on the verso and a more impermeable barrier layer between the wooden lattice and object.

Mirror plates were attached to the back of the frame. Each section of poster was then removed from its drying board. The printer’s original registration marks were visible on the recto and we used these for alignment. The poster was positioned on to the lattice frame and adhered around the edges using the lining paper margins with wheat starch paste. Where the poster sections overlapped in the central areas we wished to avoid an aqueous adhesive to minimise potential cockling, so we opted for Lascaux 360 HV, an acrylic adhesive.  Two applications of the adhesive, diluted 50:50 with deionised water were brushed out onto sheets of the same Japanese tissue we had used for the linings. Once dry, the tissue was cut into strips and folded to create long hinges (8mm wide) which were then attached to the underside of the poster’s edges, which could then be tacked down in situ with a heated spatula.  Use of the spatula also helped. as we could only just reach the centre of the object once constructed! See Fig.8.

Underpinning our choices was the very real possibility that the poster would have to be dismantled following display due to its size, and stored in the original four sections. Using Lascaux hinges on the edges in the centre and adhering only the lining paper margins around the outer edges made the attachment very reversible.

For the four-mile journey from our labs to the museum, the poster was screwed into a purpose-made transit frame and, once in the gallery, attached onto the wall with mirror plates and a supporting shelf under the lower edge. All involved were delighted to see the poster in its entirety for the first time, and the final result proved to be an impressive focal point of the exhibition. See Fig.9.

Conclusion

Although a challenging four months’ work, the final outcome was hugely satisfying. See Scotland by Train proved to be a very popular exhibition, exceeding the projected visitor figures by over a third. By conserving a large percentage of the NMS poster collection, we also improved its accessibility. Following the exhibition, the posters were easily removed from their Foamex boards by cutting the Japanese tissue margins or taking out of their frames and stored in new plan chests.

Acknowledgements

Our thanks go to our colleagues at NMS, especially those in Textile Conservation; Lynn McClean and Irene Kirkwood, who helped with the conservation and whose space we invaded; Richard Hawkes for his advice on Lascaux; Mike Wheeler and colleagues at the V&A, who provided helpful advice on mounting options; Ph7 Paper Conservation practice; Graeme Gollan, James Berry and Charlotte Park from National Galleries of Scotland.

References

• Webber, P. and Huxtable, M. 1985. Karibari – the Japanese Drying-Board; The Paper Conservator 9, pp54–60.
• Webber, P. and Norton, A. 1998. The Power of the Poster and Paper Conservation; The V&A Conservation Journal 29, pp13–17.
• Huxtable M., Wheeler M., Sandiford, M. and Webber, P. 2006. A Case Study: The treatment, display and handling of a loan of large posters; Jaques, S. ed. Edinburgh Conference Papers 2006. London: Institute of Conservation pp189–194.

Materials & Equipment

• Japanese machine-made paper RK-17, 19gsm: £398 from Conservation by Design www.conservation-by-design.co.uk
• Shoufu wheat starch paste: www.conservation-by-design.co.uk
• Frames and toughened glass: Edinburgh Arts, 26-28 West Bowling Green Street, Edinburgh
• Reemay®: www.preservationequipment.com
• 4001 Lascaux acrylic adhesive 360HV: AP Fitzpatrick www.apfitzpatrick.co.uk
• Foamex: www.roberthornedirect.co.uk

List of Figures

Fig.1. Detail of poor condition, showing tears and loss
Fig.2. Removal of secondary paper backings after immersion in water
Fig.3. A heavily damaged poster resting on the Reemay® screen during washing
Fig.4. Stretching posters following treatment
Fig.5. Lisa Cumming with the reverse of the Foamex board showing its support frame and split battens
Fig.6. Poster positioned on Foamex board
Fig.7. The wooden lattice frame for the Coronation Scot poster with layers of Japanese tissue being adhered
Fig.8. Lisa Cumming, Vicki Hanley and Charlotte Park from NGS adhering the Coronation Scot sections to the lattice frame
Fig.9. Photograph of See Scotland by Train exhibition

All images ©Trustees of the National Museums Scotland