Conservation of large-scale printed works on paper on the example of posters in lithographic technique depicting Georg Lurich

Autor: Ülle Soosaar

Number: Anno 2022/2023

Rubriik: Conservation

ill 1

The full portrait of Georg Lurich in its initial condition brought for conservation to Kanut in February 2020

ill 2

The bust portrait of Georg Lurich in its initial condition brought for conservation to Kanut in February 2020.

ill 3

Georg Lurich, one of the most famous professional wrestlers of Estonia, in his best times.

ill 4

Viljandi’s bookseller Hans Leoke in 1906.

ill 5

The library stamp of Viljandi’s bookseller Hans Leoke on the full portrait.

ill 6

Lithography press of the Adolph Friedländer printing house in Hamburg.

ill 7

Trademark and number of the Adolph Friedländer printing house on posters from the Viljandi Museum.

ill 8

Poster paper is curling due to poor quality backing cardboard and robust mounting method (gluing on cardboard).

ill 9

Extensive paper damages on the top of the full portrait, which may have been due to higher mechanical pressure (the poster was rolled up starting from the top side).

ill 10

Extensive paper losses, tears, folds, cuts and water tidelines in the face area of the full portrait that severely distorted the image.

ill 11

Previous repair and retouching of the full portrait.

ill 12

Highly decomposed surface of the poster paper under a scanning electron microscope.

ill 13

Biological contamination of the poster paper (spores, mycelium in a dormant state) under a scanning electron microscope. Under normal conditions at room temperature, biological contamination was not active, but in a humid environment of methylcellulose, the prolific mold developed on the cotton wool used to clean the paper within a couple of weeks.

ill 14

Poster covered with a prophylactic or protective facing. The purpose of the support was to fix the broken and detached areas or areas with the risk of detachment of the deformed original in their correct location before wet treatment.

ill 15

Separation of the bust portrait from the base cardboard – it was one of the most important stages of conservation work, during which the acidic base cardboard was removed as it was dangerous for the preservation of the poster due to both chemical effects and physically deformable mounting method.

ill 16

Washing the lower section of the full portrait on a vacuum washboard. Wet treatment – washing fragile and severely damaged objects in the water environment – allows to remove decomposed products from the paper (this often improves the appearance of the work and makes the paper lighter).

ill 17

Formation of a patch from a suitably shaped repair paper. The repair paper must be compatible with the original in structure, weight, density and tone. As a rule, the repair paper could always be a little lighter and brighter than the original.

ill 18

Retouching pens for the face and head of the image. Corrections of the color tone were left lighter enough than the original surface to distinguish the toned areas.

ill 19

Handling the poster was a good challenge given its size and sometimes required the cooperation of several conservators. However, the poster fixed on the drying board could be safely moved.

ill 20

Compared to photographing without a drying board, it was much easier to digitize the original that was firmly fixed to the stand and resulted in a high-quality image.

ill 21

For packing the posters of Lurich, an archive permanent box from corrugated cardboard suitable for long-term storage. Because of the format of the posters, it was also a challenge to make a suitable box.

ill 22

Storage box for Lurich posters in the storage room of Viljandi Museum.

ill 23

The bust portrait of Lurich before conservation in February 2020.

ill 24

The bust portrait of Lurich after conservation in February 2021.

ill 25

The full portrait of Lurich before conservation in February 2020.

ill 26

The full portrait of Lurich after conservation in February 2021.

The purpose of the conservation work was to prepare two posters depicting the Estonian professional wrestler Georg Lurich [ill 1],[ill 2] preserved in the Museum of Viljandi for digitization and to ensure their preservation for longer time.

 Description of the practical work is supplemented by a chapter on historical background, in which Lurich is characterised as a versatile personality [ill 3], and his partner and friend Viljandi bookseller and publisher Hans Leoke [ill 4] is introduced, because on the Lurich’s full portrait can be found his library stamp. [ill 5] In addition, a brief overview of the lithography technique [ill 6] and on the printed materials of that technique produced by Adolph Friedländer's lithography printing house [ill 7], including posters depicting Lurich, is given. The part of the printing history is based on Stephan Oettermann's catalog „Adolph-Friedländer-Lithos: ein Verzeichnis nach Nummern“ on the history of the Adolph Friedländer lithographic printing house.

The condition of the museum exhibits before conservation was so poor [ill 23], [ill 25] that it was not possible to digitize them in this form. Numerous damage and losses of paper were found [ill 8], [ill 10], which (especially in the case of a full portrait) severely distorted the image [ill 9]. Thorough conservation gave the posters the quality they needed to make copies for use. [ill 24], [ill 26]

 Conservation processes began with Lurich's breast portrait – conservator Maris Allik dry-cleaned and dismantled the poster with the necessary previous processes, and the author of this work was able to observe these processes. The author's participation in practical work began with washing the poster on a vacuum table [ill 16], as it is a process that is efficient to perform by several persons, particularly in case of large objects. The description of the conservation processes is based on work done with a full portrait of Lurich. [ill 14], [ill 15], [ill 17], [ill 18] As the conservation plan was generally similar for both posters, the individual differences that emerged during the work are highlighted separately in the description. For these large and severely damaged posters, the best solution for conservation was supporting them with a full japanese paper backing.

 Material studies were also carried out, which included examination of the condition and origin of paper fibers, determination of lignin content and additives. Studies confirmed that paper of the poster has been severely degraded over time by various factors, in some places held only by printing ink. The posters were printed on low quality paper, which could be produced using both recycled rag paper and wood pulp. [ill 12] It was practically impossible to identify specific wood species because the wood fibers were extremely decomposed and lost their original shape during repeated processing. [ill 13] Analytical studies concluded that chlorine, aluminum and silicon-containing substances (chlorine compounds, alum, kaolin) were used in the manufacture of the paper.

 As expected, the biggest challenge in this conservation work was that the posters were large objects in terms of the usual parameters of the works on paper. The preparation of work surfaces (table, vacuum table) as well as precise planning of work processes (washing on a vacuum table, backing, digitization) required non-traditional solutions. Some of them required the cooperation of several conservators. The posters had to be dryed on a drying board after conservation because there was no paper press of a suitable size. The larger poster, consisting of two sheets, was divided in two during conservation and was processed in separate parts. It was recommended to digitize full portrait while still attached on a drying board to achieve a high-quality result. [ill 19], [ill 20] Making a large archival permanent box for storing the posters required combining and manual work. [ill 21] It is also difficult to find a place for such a large storage box in the museum's storage rooms. [ill 22]

The article was translated by the author