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Seeing through the years: The Conservation of Transparent Papers in the Parliamentary Archives Collection Part II

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This blog was written by Zoe Voice, Preventive Conservator.


Welcome back for part two of our series on transparent papers. In the last post, we took a look at what transparent paper is, how it’s made, what examples we hold in our collection, and the condition challenges they present to conservators to repair and preserve. We’ll now turn to look at the ways Collections Care treated transparent papers in the past, in the 1970s-80s, and contrast that to how we now approach these items during our Collections Care Pilot Project.

How have they been treated in the past?

A survey is currently being conducted at the Parliamentary Archives looking through all of the deposited plans – around 30,000 records. The plans are found stored in a variety of ways – some are simply rolled, wrapped in archival quality paper and stacked onto shelves as the picture below shows, others are stored in boxes, and some have been bound into large books.

A repository in the Victoria Tower, on floor six. Showing how many of our deposited plans are stored – rolled up in archival quality paper and stacked on a shelf. The colourful tags attached to the rolled plans denote their year – this range between 1890 and 1906.

To the best of our knowledge, the Archive Bindery that existed here in the 20th century undertook some interventive treatments on records in the collection, including some plans. The tracing paper records bound into books. When handling some of these records, you may not even realise that they’re drawn on very thin, transparent papers, due to the amount of treatment that they had received. From preliminary assessments, we believe that these have all been “laminated” using a spun polyester fabric and PVA, or another synthetic adhesive, pressed under heat to flatten and set the glue. As some of the inks on these items also look like it has run from the adhesive being applied, we suspect some solvent-based adhesives may also have been used on some. Many of the items that have received this treatment also seem to be in perfectly good condition, suggesting that they were uniformly treated in this way, rather than intervening with an item only when necessary. This is not a treatment that we would consider today. Current conservation ethical methodology in archives is to strive to intervene as minimally as possible, and what is necessary for their survival, and when we do undertake treatments it is with materials that to the best of our knowledge will not damage the item and do not impede with their appearance or the information they contain.

A deposited plan on tracing paper which has been laminated from and back using a synthetic textile and an adhesive.

A pamphlet found in Collections Care Studio dated 1973 discusses the different types of heat-set treatments to laminate paper, such as Lamatec, and we have found come treatment notes attached to treated records dated 1980, so we might assume this was undertaken sometime around this time. We are unable to take any action with these records – indeed, they are so robustly conserved that they are very strong and handleable, and the reversibility of the lamination is effectively impossible. Nevertheless, these examples are items of conservation history, as well as of Parliament’s.

How are they being treated now?

The Collections Care Team at the Parliamentary Archives is a team of five, made-up of: Collections Care Manager, Katerina Laina, Collection Studio Manager, Zofia Wyszomirska-Noga, Book and Paper Conservator, Jillian Harrold, Senior Conservation Technician, Connie Search, and Collections Care Trainee, Me, Zoe Voice. The goal of Collections Care is to facilitate the research, learning and access to our collection by stabilising, monitoring and managing the deterioration of our material records. Our work comes through mainly: researchers requesting to see documents in our search room which are in fragile condition, items being exhibited in displays and events or used in outreach activities, which need to be mounted in a way that doesn’t cause damage, records needing to be digitised but cannot be in their current state i.e. if they’re rolled, or preparing items due to be loaned out to other institutions. We care for our collection by managing their proper storage environments and offering digitised copies as an alternative format, and with more interventive, hands on approaches which include cleaning, flattening, tear repair, washing, rehousing, lining etc. All of this means that our collection can be enjoyed by as many people as need access to them now and ensures that they are maintained in the highest possible condition for future access also.

The deposited plans at the Parliamentary Archives are currently being surveyed by a team who is ensuring that the information on our object catalogue is accurate and complete for each plan and its associated documents and flagging any plans with condition or storage concerns. Many of the items are in poor condition, i.e. they are unable to be opened and handled without causing damage, and are transparent paper plans, which need to have interventive treatment in order to be accessed. In response to this, Collections Care have launched a pilot project which has selected five represented examples of transparent paper plans highlighted by the survey as in very poor condition. We have been researching treatments using available literature and case studies written by other conservation professionals and colleagues, as well as consulting our team’s wealth of experience, to collate and try different treatment methodologies that we can apply to these different tracing paper plans, to test and reflect on how we can best treat the items, with the aim to formulate a reliable methodology for our collection.

Fortunately for me as the Collections Care Trainee, I am encouraged to pursue as many training opportunities as I am able. We were a few months into the pilot project when I saw there was a two-day conservation workshop held at Hildegard Homburger’s studios in Berlin coming up. Homburger is an eminent paper conservator with over 35 years of experience in the field and has specialised, amongst other things, in the conservation of tracing paper. We saw this as an opportunity for me to learn more about this material and practise methods of repair in order to enrich my pilot project objects. I flew to Berlin in early October to attend this two-day workshop - only myself and five other conservation professionals from institutions across Europe were lucky enough to book a space. We were led through a series of lectures and hands-on treatments testing different methods of repair and exploring different case studies Hildegard has encountered throughout her career, and which of these methods she has honed and recommended. It was an incredible opportunity to learn from both Hildegard and my peers’ experiences with transparent papers, and also to be able to explore different methods freely using mock-ups. I returned full of ideas and a greater understanding of the material I was working with.

We have so far completed the treatment of two plans and are currently undertaking treatment on a further two. The two that we have treated so far were both in very different conditions and so we were able to trial different methods of repair. The first impregnated tracing paper is a plan of Stockton Gas Works from 1857. It was in otherwise good condition, save for the large tears. This paper was accompanied by its original blue paper cover, which had taken the brunt of the damage and surface dirt. Our aim was simply to flatten under light pressure and then stabilise the tears to prevent them from becoming detached losses in future. Usually, with tear repairs, we would use patch repairs, where a lightweight but strong paper is adhered over the tear to hold it in place. With this transparent paper though, we wanted to try a method which did not add too much bulk or cause tension in the tracing paper by adding another layer. Additionally, as the record had a paper cover already that it would go back into it was not as exposed as other examples in the pilot. So, instead, we used individual paper fibres teased out of a high-quality, long-fibered Japanese Kozo paper. We laid each fibre down across the back of the tears, almost like stitches, while the paper was held in place using a suction table. The visual effect is very good - the paper fibre repair was barely visible both on the front and the back of the paper, except in raking light as is shown in the photograph below. After treatment, the repairs have held together perfectly and are expected to sufficiently withstand handling by users in future.

Detail of the repairs we made on the back using single fibres pulled out of the Japanese Kozo paper. This image shows the repair area in normal light, where the repair is effectively invisible.
This image shows the repair area when a beam of light is shone across it at a low raking angle, revealing the paper fibres laid across the tear edge.













The second tracing paper is from 1863 of Coventry Market House. It had been glued onto a thicker, non-transparent paper which was pasted onto a canvas lining. We assume this was done because the tracing paper is very thin, so this backing would have aimed to protect it when handling. However, unfortunately, over time backed items tend to actually be damaged by the backing, particularly when it is backed by a thicker paper or fabric, as these are much stronger than the item that is it's pasted to, which means that if the fabric or the paper swells due to humidity or shrinks due to dryness or is handled means that it will pull the thinner paper and then often weaken over time. This paper thus had multiple losses and tears which were far more extensive than the first item. We started by attaching a facing paper onto the front of the work, which is effectively a temporary backing which holds all the pieces in place while we remove the backing. Unlike the backing we chose a very thin lightweight paper, a 5gsm Kozo, with a very flexible adhesive, funori which is a seaweed mucilage from Japan, so this wouldn't cause any further damage and was easy to remove. The facing meant that we were able to turn this tracing paper onto its front and remove the fabric backing using a scalpel and spatulas and then backing paper, again with a scalpel and spatula, without damaging or losing any pieces of the tracing paper or the information that it contains. You can see me removing part of this backing in the image below. Once those were removed, we were then able to apply a conservation grade backing, which, similar to the facing, was a much thinner lighter paper, a Gampi paper this time, and a flexible adhesive, wheat starch paste. This means that unlike the backing that it was currently on it would not pull tear the tracing paper as it was a much more sympathetic material. In both of these instances the outcomes were very pleasing both visually and in regard to their care, as these transparent papers have now both been stabilised and will enjoy a much more graceful ageing process.

The plan is reversed to allow me to gently lift off the thicker backing paper using a metal spatula and a scalpel. The facing paper my colleague applied holds the plan in place so we do not displace any of the pieces. The light table allows me to distinguish clearly between the paper that needs to be removed and the transparent paper – even tiny pieces. Coventry Market House, 1883, Parliamentary Archives, HL/PO/PB/3/plan1863/C11

We are now working on two much larger papers, both of Bowness from 1884. They present new issues of being a stronger, thicker paper, but also very brittle, and so have extensive tears and snapping along the fold lines where they had been folded. They have become raised and undulating along these lines, and so have been humidified using a small amount of water vapour to relax and flatten – see the images below before and after 20-minute humidification through Gortex. Further, the item that Jillian is working on has losses extensive enough that there are gaps which will need infilling, where a piece of tracing paper or another paper of a similar thickness and feel is shaped to fill the void, stabilising the gaps and allow for safe handling. We are using two different adhesives for these papers – isinglass, a traditional Russian adhesive made from the swim bladder of the sturgeon fish (we did not buy this isinglass and recognise the ethical considerations of harvesting animal products, however, the properties of isinglass on paper is irrefutable and we found this isinglass in our store room from previous generations of colleagues who worked here so as not to waste it we thought it would be a worthwhile avenue to explore), and Klucel G, a synthetic cellulose polymer adhesive. We have made this using industrial methylated spirits (IMS) which is nearly-pure alcohol, meaning that we can use this adhesive on media which is water soluble such as iron gall ink, a historic and very common ink used on all kinds of documents and artworks, and that becomes water sensitive with age, which Jillian’s tracing paper has.


Before the plan was layered on both sides with Gortex – a semipermeable membrane that only allows through fine water vapour rather than liquid water – and wet blotter paper. Bowness Local Board (No.1), 1884, Parliamentary Archives, HL/PO/PB/3/plan1884/B21


After 20 minutes, water vapour just passes through enough to start to expand the fibres and give them some flexibility – what we call ‘relaxes’. Note how the paper after humidification is immediately flatter. Now we are able to apply weight to encourage the paper to stay flat.


This project has so far proven to be a fruitful exploration into the conservation of transparent papers. It has brought me a greater understanding of the work of our predecessors in the archive, our colleagues from around the world, and the items in our collection on transparent paper. I have been able to gain skills and a degree of confidence when approaching these materials, and I am looking forward to continuing this work. As the survey of Deposited Plans continues, we look forward to being able to improve our online catalogue with more information in what these records contain, as well as their condition and housing.

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