Claire Valero – Workshop on Pulp Repair of Archival Documents on the Vacuum Table

This workshop took place at the National Archives of Ireland (NAI) in Dublin on March 7th and 8th, 2017. It was led by Alan Buchanan, independent Paper Conservator and tutor at Camberwell College of Art, and Ciara McQueirns of the Paper Conservation Studio in Dublin. It was a great opportunity to learn about this conservation technique as an emerging conservator.

The purpose of this workshop was to present the methodical visual system to create matching infills for missing areas in archival documents with coloured paper pulp, a strong and effective way of repairing and retouching documents at the same time.

Over the two days the workshop featured two complementary types of presentations: theory (with explanations of the technique’s background(1), concrete examples(2) and material needed), and practice (with trials for colour matching and actual repairs on damaged documents).

The method was developed by Alan Buchanan, based on Norton’s concept of Depth of Shade (DOS)(3) and answers the conservator’s questions –  “how to make paper pulp on a large, repeatable scale from any paper, and how to tone paper pulp on an equally large scale.” (4).

The ethic is that,“the repair should be discernible but should not distract the eye”. Among the advantages of this technique we can cite its fastness of execution (once practiced), the aesthetic aspect of the repair with a smooth surface, the strong bond between the repair and the document, yet its high reversibility and the lack of adhesive.

The method of coloured pulp repair is separated in two distinct phases: first is the choice of the colour best suited for the repair by making a swatch and comparing it to made-to-measure colour charts. The second step is the repair in itself with a satisfactory colour of the infill. The final colour can be adjusted during the process and several colours can be combined to make a gradation infill.

Once the theory is assimilated, then comes the fun part – practice! The colour is first selected by comparing the lost area to 8 coloured charts (1). A small quantity of paper pulp is made using precise quantities of blue, yellow and red paper samples in order to achieve the right tone. Then the proportions of coloured paper samples are weighed and mixed with water in a blender for a short period of time. This is to ensure that the fibres are short, because too long fibres can create lumps and will show into the repair.

1. The document is compared to the coloured charts under natural light.

The mixed pulp is applied with a nasal decongestor or a pipette in a mould on the vacuum table covered with Melinex (2), polished with a bone folder over a piece of Melinex and dried with the suction and a hairdryer (3). The swatch is then compared again to the chart under natural light. When the colour is right, it can be applied to the document.

2 b
2. Application of the mixed pulp with the nasal decongester..
3 bis_3
3. Drying the patch with the hairdryer.

For this workshop, the OS Triangulation Maps taken from the NAI collection were prepared. They were of large format, dusty, mouldy and suffered from many tears and losses. The maps were first dry cleaned, washed and the tears were repaired with Japanese paper to be stable enough to allow manipulations and paper pulp infills (4).

4. Detail of losses on the Triangulation maps.

Adjustments were made to the method, according to the particularities of the studio and the material such as the lack of a lightbox under the vacuum table, the use of Saatilene sheets instead of thin bondina to avoid the pulp sticking to the surface and adjusting the pressure of the table to avoid marks due to suction.

The vacuum table is covered with Saatilene. Then, thick Melinex is added (75 microns), leaving space for the infills. An accurate mask in thin Melinex (12 microns) is made for the shape of each infill and placed on the Saatilene. The document is placed on top, face down (5).

5. Illustration of the superposition of the different layers.

The vacuum is switched on, the pulp is dropped carefully on the document, then polished and dried (6). The repair is resistant, reversible and aesthetically pleasing.

Alan Buchanan supervising the drying step of a paper pulp application.

As a young conservator, this workshop was very enriching and allowed me to experiment a technique that I only knew theoretically. As a result, it helped me to better understand this method with the importance of organization beforehand and good material, of precise measures and gestures and of natural light for colour matching.

Claire Valero

Conservation Intern at the National Archives of Ireland.


  1. Keiko Mizushima Keyes, A manual method of paper pulp application in the conservation of works of art on paper, AIC Preprints of the fourth annual meeting of 29 May – 1 June 1976
  2. Helga Joergens Lendrum and Ciara McQueirns, The use of infilling with dyed paper pulp: Conservation of a 19th century document including infilling holes with predyed cotton rag paper pulp as devised by Alan Buchanan
  3. Alan Buchanan, A Methodical visual system to create matching infills for missing areas in works of art on paper by dyeing cotton rag papermaking pulp different shades of yellow, red and blue, The Quaterly 65, January 2008, pp.20-28
  4. Patricia Hamm, Second Generation Wet Paper Pulping, The book and paper group annual 22, 2003, pp.27-31


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