The digitisation of ‘Vergadertafel’ (Axel and Helena van der Kraan, 1976)

Author: Esmee Postma (Museum Boijmans Van Beuningen)
Peer reviewer: Rony Vissers (PACKED vzw)

This case study deals with the artwork ‘Vergadertafel’ (Conference table), created in 1976 by the Dutch artist couple Axel and Helena van der Kraan. Within the framework of the DCA project this artwork has been professionally photographed, digitised and documented in Museum Boijmans Van Beuningen’s collection management system TMS.1 During the process several problems and questions emerged that will be discussed in this case study. Artworks that at first glance don’t seem problematic to re-install and to digitally photograph do raise a number of questions and problems during the actual digitisation process. For 'Vergadertafel' and other artworks certain questions had to be considered, such as “does the artwork need to be restored before it's photographed?”, “how does this artwork need to be installed and how can one find out how to do so?”, “how to maintain the intrinsic characteristics of the artwork when reproducing it digitally?” and “how can one make the resulting digital reproductions online accessible and preserve them in a sustainable way?”. By taking ‘Vergadertafel’ as an example this case study will show some of the issues that Museum Boijmans Van Beuningen encountered when digitising a part of its collection within the framework of the DCA project.

1. Short description of the collection
Museum Boijmans Van Beuningen is one of the oldest museums in the Netherlands. In 1849 the lawyer Frans Jacob Otto Boijmans donated his art collection to the city of Rotterdam. With the acquisition of the collection of businessman Daniël George Van Beuningen in 1958, the second part of the museum's name was added on. Over the decades the collection expanded into a broad range of fine art, crafts and design. The museum houses a unique collection of paintings, sculptures and everyday objects, dating from the Middle Ages until today. The collection of prints and drawings is one of the finest in the world. Among the most famous artists whose work is permanently on display are Hieronymus Bosch, Pieter Bruegel de Oude, Rembrandt, Claude Monet, Wassily Kandinsky, Vincent van Gogh, René Magritte and Salvador Dalí.

At the beginning of the sixties Museum Boijmans Van Beuningen started systematically acquiring works for its contemporary art collection. Before only a few contemporary artworks had been acquired, through occasional gifts and purchases. At the same time, the museum started its ‘Surrealism’ collection, which is currently an important sub collection and is continuing to grow (for instance with the acquisition of works by artists like Alexandra Bircken who are still related in a particular way to ‘Surrealism’). While retroactively collecting older contemporary works, Museum Boijmans Van Beuningen also started collecting recent contemporary artworks. This double approach has been continued since then.

Besides ‘Surrealism’ one can distinguish a couple of other directions in the contemporary art collection: ‘Drawings’ and ‘Film and video works’. The museum currently collects artworks from contemporary artists, like for instance Paul Noble, whose main artistic activity is the creation of drawings, especially monumental ones. Museum Boijmans Van Beuningen has also collected film and video art since the seventies, for instance by artists like Anri Sala and Robin Rhode.

Currently the collection of modern and contemporary art comprises approximately 7,500 artworks. Besides this collection Museum Boijmans Van Beuningen also holds a collection of 33,000 drawings that is part of the collection modern and contemporary art.

Apart from the collection display the museum annually organises around twenty-five temporary exhibitions connected with the various sub collections. Most of the current exhibitions at Museum Boijmans Van Beuningen display modern and contemporary art.

2. The artist

Axel Erik van der Kraan (born in Rotterdam, 1949) is a Dutch sculptor and graphic artist. His wife Helena van der Kraan (born in Prague, 1949) is trained as a painter and graphic artist. Together, during the seventies, they created wooden sculptures of humans and objects that perform everyday activities with the use of various mechanics. The figures and machines are larger than life and depict the doom of monotonic existence. From the eighties onwards their interest shifted to notions of violence and aggression with sculptures of soldiers, tanks, knights and horses.

A fascination for technique plays a particularly large role in the oeuvre of Axel van der Kraan. Often his works are assemblies made of wood or metal and emphasise the mechanical constructions that always remain visible. The wooden sculptures consist of simple parts; the figures are mostly constructed of one trunk for the head and a second trunk for the body. The meaning of the work lies in the repetition of the mechanical movements: the semi-absurd installations exhale a cynical view on the thoughtlessness of human behaviour.

‘Vergadertafel’ (Axel and Helena van der Kraan, 1976)
Photograph: Jannes Linders. Courtesy: Museum Boijmans Van Beuningen

Apart from the sculptures and installations Axel van der Kraan made numerous drawings, woodprints and veneer prints. From the seventies Helena van der Kraan also focussed on photography as a medium. She started by documenting the artistic performances of her husband. Her photos show an emphasis on forms, lines and patterns, revealing her experience as a graphic artist.

3. The artworks

‘Vergadertafel’ (1976) was exhibited at Galerie Espace, Amsterdam, 15 April to 20 May 1978 and the Fundatie Kunsthuis (Foundation of Art) Amsterdam, 17 May to 29 June 1979. In July 1979 the artists donated the artwork to Museum Boijmans Van Beuningen. During the period 1989-1993 the museum acquired several installations, sculptures and prints by the couple. ‘Vergadertafel’ is their earliest work in the collection.

‘Vergadertafel’ consists of a chassis with a built in mechanism, a tabletop and five figures. On the chin of each figure a nylon cord is attached using an iron eyelet. This is subsequently attached by a small hole in the tabletop via a pulley with the other end to an s-shaped plywood lever at the base. The levers are driven by an electric motor that makes the chins move and the figures seem to converse. The artwork portrays a human, everyday scene: five figures at a table having a conversation. Simultaneously the human act is aligned with the mechanical movement. The figures consist of solid heads that are attached to box-like torsos. Facial expressions and other characteristics are missing, while the chins move compulsively and endlessly: they are prototypes of the obedient man.

‘Vergadertafel’ (Axel and Helena van der Kraan, 1976) (detail)
Courtesy: Museum Boijmans Van Beuningen

‘Vergadertafel’ (Axel and Helena van der Kraan, 1976) (detail)
Courtesy: Museum Boijmans Van Beuningen

4. Status

The artwork ‘Vergadertafel’ was documented and registered in the TMS collection management system. The metadata scheme is Boijmans-Basis. The artwork was also successfully digitally photographed. The two resulting high-resolution digital reproductions are on a Windows 2007 server. Low-resolution copies are stored in the TMS collection management system. The metadata and a low-resolution reproduction are made available through Museum Boijmans Van Beuningen’s Online Collection2 and Europeana3.

5. Definition of the problems

The main goals for the digitisation activities of Museum Boijmans Van Beuningen in the DCA project are
• to make the selected artworks available online;
• to eliminate the backlog in registering, conserving and photographing its collection.

Museum Boijmans Van Beuningen already has two websites that present part of its collection online. In total almost 8.000 objects are accessible via its Online Collection and ALMA4. For the DCA project the museum exclusively focussed on three-dimensional works: installations, sculptures and assemblages.

To eliminate the backlog in terms of registration, Museum Boijmans Van Beuningen is following the Boijmans-Basis principle for the DCA project. This basic registration consists of a number of fields that must be completed so that a record can be approved or 'validated'. This means that all elements of the description are verified step by step for each selected artwork and completed if necessary. A quality photographic image also accompanies the description of each artwork. Because the DCA project often involves larger and more complex artworks, documentation related to how the objects are assembled and their condition must be provided in addition to the details needed for the Boijmans-Basis principle.

The four main questions that Museum Boijmans Van Beuningen faced during the digitisation process were:
• does ‘Vergadertafel’ need to be restored before digitally photographing it?
• how does ‘Vergadertafel’ need to be installed and how can one find out how to do so?
• how to maintain the intrinsic characteristics of ‘Vergadertafel’ when reproducing it digitally?
• how to make the resulting digital reproductions of ‘Vergadertafel’ accessible online and to preserve them in a sustainable way?

6. Resolutions for the problems

The digitisation process of ‘Vergadertafel’ was made up of several steps:
1. definition of digitisation goals;
2. definition of digitisation budget;
3. copyright clearance;
4. definition of quality requirements and the digitisation task;
5. search for a subcontractor;
6. preparation for digitisation;
7. actual digitisation;
8. quality control;
9. cataloguing digital files;
10. archiving digital files;
11. making digital reproductions accessible online.

General preparation
The first two steps were already taken before the start of the DCA project in January 2011. It was decided that ‘Vergadertafel’ would mainly be digitised for the purpose of access but that the quality of the digital reproductions had to be as high as possible to allow high quality access and to be able to use them also for other purposes. Access does not only imply online access for the general public but also for the museum staff. It is also very convenient for them to be able to view a photograph of the artworks within the museum’s collection management system. Contrary to the general public the museum staff can always visit the museum’s depot to view works that are not on display in the museum but some artworks cannot be easily viewed there, especially those that consist of several parts or that need to be installed. The digitisation of ‘Vergadertafel’ also offered the museum the opportunity to check, update and enrich the information stored in the museum’s collection management system about the artwork. The digitisation budget was also already defined during the preparation phase.

The goal of copyright clearance was to obtain the permission from the artists to make a reproduction of their work accessible online. The museum directly got in contact with both artists to obtain this permission. A proposal for a license agreement was sent to them accompanied by a letter from the museum, and was returned with a signature by the artists. With some other artists this process was much more difficult. Another goal of copyright clearance was to obtain the permission from the photographer for the use of his digital images by the museum. This permission was negotiated and agreed as part of the subcontracting agreement. When the photographer’s images are used, the name of the photographer is mentioned as part of the credits.

For the digitisation part of the DCA project, Museum Boijmans Van Beuningen decided to collaborate with photographer Jannes Linders5. He is not employed as a member of the museum staff but is subcontracted. The choice of Jannes Linders as subcontractor was based on the balance between the subcontracting fee and the quality offered. After the comparison of several quotes the museum started the DCA project with another photographer, but decided to change to Jannes Linders during the project because of quality issues. Jannes Linders is also based in Rotterdam, and for twenty years the museum has regularly worked with him. He has experience with photographing large spatial artworks, which was important within the framework of the DCA project.

Digitisation location
It was decided that ‘Vergadertafel’ would be photographed at an external depot of Museum Boijmans Van Beuningen. Contrary to many other artworks this work from the museum collection was not photographed in a public museum room. To spread information about its participation in the DCA project the museum decided that a large part of the digitisation work would take place in a museum room that is accessible to the public. There was an information notice about the project in the room and on the window facing the street. In the museum visitors could also consult a list with an overview of which artworks were going to be digitised and when. ‘'Vergadertafel’ was however one of the artworks that was not digitised in this public museum room but in a temporary photo studio installed in the museum’s external depot. The advantage of this was that transport of the artwork could be avoided. Transporting such an artwork requires considerable logistical preparation and proper planning.

How to install ‘Vergadertafel’?
When installing the artwork for digitisation museum staff first had to check whether all components of the work were still present and functioning. Often artworks have not been assembled for a long time. ‘Vergadertafel’ contains a motor that needs to be connected by nylon chords to the human figures around the table. The motor makes the heads of the figures move. Another thing that needed to be checked and decided upon was the direction of the figures and their distance from the table. There was no written information about this available in the museum. It was decided that the figures should be placed directing to the tabletop. This decision was based on archival photos and one in an exhibition catalogue of the Stichting Beeldende Kunst Amsterdam (Visual Arts Foundation Amsterdam) of 1988. Museum staff also discovered during the installation for digitisation that the length of the nylon cords that need to be connected to the motor actually determines the distance between the different components. These need to stand without being taut. When they are taut the mechanism stagnates in the chassis, while the engine is running.

‘Vergadertafel’ (Axel and Helena van der Kraan, 1976)
Copyright Dick Wolters. Courtesy: Museum Boijmans Van Beuningen

When installing ‘Vergadertafel’ it became clear that the legs of the table are slightly damaged, but not insurmountably. There are also some cracks in the heads of the figures. It is not clear whether the cracks were already there at the acquisition of the work or that it is due to old age. All components of the work were already numbered making it clear in what position they should be placed. The position of the tabletop and frame is indicated by the numbers I and II. The sequence of the five figures is indicated by the letters A to E, which are affixed both to the frame of the table and the bottom of the figures.

Old installation instructions ‘Vergadertafel’ (Axel and Helena van der Kraan, 1976)
Courtesy: Museum Boijmans Van Beuningen

How to photograph ‘Vergadertafel’?
After the artwork was installed in the temporary photo studio in the depot, the museum staff and the photographer had to decide upon how to photograph it. A crucial question with a three-dimensional work like ‘Vergadertafel’ is from which angle it should be photographed. It was decided that the photographs should be taken from two different angles. This resulted in two different photographs, each portraying the complete artwork; the museum did not ask the photographer to create photographs of details of the artwork.

Museum Boijmans Van Beuningen always involves a museum curator in the digitisation process. They, together with the registrars who are present at the photo shoot, determine how the artwork is photographed, and how many times. If it contributes to a better understanding of the piece, then photographs will be taken from two or more angles. Museum Boijmans Van Beuningen always tries to obtain a photographic image that does the artwork justice. This also means that the photographer needs to take into account the properties of the room and the light when preparing the pieces for digitisation.

Another question was related to the movement of the artwork. It was decided that ‘Vergadertafel’ should be photographed in a standstill position. During the photo shoot the electric motor was not activated. Since attaching the nylon cords to the levers made no visual difference with the motor turned off, they were simply inserted between the tabletop. However, after the photo shoot the electric motor was turned on for conservation purposes, to check whether it was still functioning. Then it was possible to consider whether the activated installation shouldn't be recorded on video, but such a video recording wasn’t made. Many other three-dimensional photographs with moving components can sufficiently be digitally reproduced through digital photography because one can photograph their (movement in) different stages, but this is not possible for ‘Vergadertafel’. Its movement is too minimal to clearly reproduce in a photographic sequence; the figures around the table only nod their heads.

The quality requirements
Museum Boijmans Van Beuningen defined the quality requirements for the digital reproductions in collaboration with the photographer. For digitising artworks on paper the museum uses the Metamorfoze guidelines6. Since these guidelines do not really apply to one-on-one for large three-dimensional objects, it is difficult to use them for taking digital photographs of the latter. With regard to technical parameters there are few differences compared with the approach used for digitising other types of artworks. It was decided that the final result of the digitisation process should be an Uncompressed Baseline IBM TIFF v6.0 file, with a size of approx. 4961 x 7016 pixels,7 a resolution of 300 ppi, a colour depth of 8 bits per primary colour channel and a Adobe RGB (1998) colour profile.

The actual photography
To produce the reproductions photographer Jannes Linders used a Hasselblad 500 CM camera8 with a 22 megapixel Phase One P25+ digital back9. The maximum size of the images created with this digital back is 5436 x 4080 pixels, but with the use of the optional Phase One FlexAdopter and Capture One software supports, automatic stitching of two or three images is possible resulting in a maximum image size of 7991 x 5436 pixels.

The camera was used with a Carl Zeiss Planar 2.8/80 T* lens10. No natural daylight was available in the temporary photo studio in the depot. The lighting was done with three to five Broncolor and Profoto flash heads. The flash heads had to flash twice to get a sufficient amount of light to be able to use a F 16 lens opening, with an ISO speed rating of 100 ASA. The White Balance setting was ‘Flash’. The shutter speed was 3 sec. An 18% grey card was photographed together with the installation.

Photographing ‘Vergadertafel’ took approximately one hour. The digitisation team normally digitised eight to nine different artworks per day. The team consisted of several persons; beside the photographer, several museum staff members were also present. When artworks were digitised in the depot, there were two art handlers, a registrar and a trainee museum curator. The art handlers took care of moving and installing the artwork, the registrar of checking, updating and enriching the condition report and the trainee museum curator of checking, updating and enriching the metadata and installation instructions. The registrar decided on the spot whether the artwork is correctly installed. The proper installation is always researched and discussed in advance with the museum curator. The documentation folder (on paper) on the specific artwork is also consulted. Afterwards the museum curator checks the metadata that is updated and enriched by the registrar. The museum curator needs to validate the metadata and the reproduction in the collection management system before it is made available online. An authorisation from the museum’s TMS application manager is also required.

The original results of the digital photography process were RAW files (IIQ Raw L)11 with a colour depth of 16 bits per primary colour channel. These RAW files were transcoded to TIFF files with a colour depth of 8 bits per channel. Some colour correction and retouching was also done. The software used for the transcoding, retouching and colour correction was Capture One Pro 712 and Adobe Photoshop CS513. The monitor used was an Eizo CG243W monitor14. This monitor was calibrated with the Eye-One colour management system (developed by Gretag McBeth)15 and Eizo’s Color Navigator 616. The original technical metadata produced in the camera is no longer available in the TIFF files.

Updating and enriching metadata and conservation documentation
Indirectly the registration and documentation of the works that were part of the DCA project led to a change in the way the works from the collection of Museum Boijmans Van Beuningen are registered and documented. The difficulties that arose during digitising artworks such as ‘Vergadertafel’, that need more specific instruction on how to install them, were the trigger for an additional instruction field in the TMS collection management system to collect this information retroactively. In the future the museum curator and registrar will fill in this new instruction field the moment a new work is acquired. This is to avoid artworks being exhibited in an inappropriate way.

In the past such instruction information was stored on paper in folders, but for the Museum Van Beuningen it has become important to enter such information in the TMS collection management system because it is then easier to search through and reuse the information. Everything is in digital format and is saved together. Along with the team responsible for the restoration of paper works, the museum had already developed a way of entering and exporting condition reports in TMS. The museum wanted to build on this and develop an equivalent for three-dimensional installations.

The metadata scheme that Museum Boijmans Van Beuningen uses is the Boijmans-Basic. This basic registration consists of a number of fields that must be completed so that a record can be approved or 'validated'. The fields contain an inventory number, the title, the creation date, the creators, the size, the materials and techniques used, the object type, shelf-mark, the provenance, the acquisition date, the acquisition method and the acquisition status. Within the Boijmans-Basic the museum uses a number of controlled vocabularies. The TMS collection management system offers the possibility of relating this object-related information to other types of information, for instance information on components, persons and organisations, images, exhibitions, loans, shipments and events.

Both the registration and documentation of ‘Vergadertafel’ has been checked, updated and enriched as part of the digitisation of the artwork within the framework of the DCA project.

Additional preservation actions
In addition to filling in the new installation field in the collection management system TMS, special attention should be paid to the way in which artworks are packaged and preserved when the work is not exhibited and stored in the depot. In the case of ‘Vergadertafel’ it became clear that the packaging of the components was not optimally suited for preservation. Previously, the components were packed separately in bubble wrap. After installation for digitisation, it was decided that the components should be packed separately in Tyvek.17

Delivery and storage of the digital reproductions

The photographer handed over all digital files to Museum Boijmans Van Beuningen on DVD-ROMs. These disks contain the high-resolution TIFF archival master files.

At the museum the high-resolution archival masters of the digital reproductions are stored on a Windows 2007 server. Only one staff member has direct access to these files in order to move them from a general file folder for high-resolution images to a file folder that corresponds to the sub-collection to which the artwork belongs and to create derivative jpeg access copies. These low-resolution copies are stored in the TMS collection management system linked to the metadata on the portrayed artworks.

Until recently the media server only contained file folders with files. Currently the museum has a freelancer who checks and cleans all file folders, and transfers the content to Adobe Bridge, a digital asset management system. This system allows to add and extract metadata.

Back up of the files on the media server is made daily on data tape. Monthly and yearly back-ups on data tape are stored in a vault in a bank. A subcontractor manages the digital storage of the Museum Boijmans van Beuningen. More detailed information about the digital storage and preservation currently can’t be provided as the subcontractor has very recently been changed.

Online access

The artworks that are digitised within the framework of the DCA project are online, and are accessible through Museum Boijmans Van Beuningen’s Online Collection. In this online collection presentation platform metadata and a low-resolution reproduction are displayed.

‘Vergadertafel’ (Axel and Helena van der Kraan, 1976)
Photograph: Jannes Linders. Courtesy: Museum Boijmans Van Beuningen

7. Results
The results of the digitisation of ‘Vergadertafel’ are two different digital reproductions, each portraying the artwork from a different angle. The Museum Boijmans Van Beuningen holds a master file and an access copy of the two digital reproductions.

The technical characteristics of the master files of ‘Vergadertafel’ are:
• size: 5263 X 7017 pixels
• resolution: 300 ppi
• bit depth: 8 bits per primary colour (i.e., 24 bits in total)
• colour space: RGB Colour
• colour profile: Adobe RGB (1998)
• compression: None (uncompressed)
• endianness: big-endian (IBM)
• file format: Baseline TIFF v6.0
• file size: 110,8 MB

The technical characteristics of the access copies of ‘Vergadertafel’ are:
• size: 1311 X 1748 pixels
• resolution: 72 ppi
• bit depth: 8 bits per primary colour (i.e., 24 bits in total)
• colour space: RGB Colour
• colour profile: Adobe RGB (1998)
• compression: lossy
• endianness: big-endian (IBM)
• file format: JPEG
• file size: approximately 1 MB

The Museum Boijmans-Van Beuningen now also holds updated and enriched metadata and conservation / installation documentation on ‘Vergadertafel’ in its TMS collection management system.

8. References
• Peters, Philip. Axel en Helena van der Kraan, exh. cat. Haarlem: Uitgeverij De Toorts, 1988.
• Groot, Elbrig de. Axel en Helena van der Kraan, exh. cat. Rotterdam: Museum Boijmans van Beuningen, 1989.
• Vissers, Rony. Interview with Nynke van der Wal (Museum Boijmans Van Beuningen), 2012,

9. Contact details of the author
• Esmee Postma (.(JavaScript must be enabled to view this email address))
• Noor Mertens (.(JavaScript must be enabled to view this email address))

10. Footnotes
1 The Museum System. For further information, see
2 Accessible through
3 Accessible through
4 Accessible through
5 For further information, check
6 For further information, see and
7 The width of the A2 format is at 300 dpi 4.961 pixels (if vertical) or 7.016 pixels (if horizontal).
8 For further information, see
9 For further information, see
10 For further information, see
11 ‘IIQ Raw’ is a short term for Intelligent Image Quality Raw, Phase One’s proprietary RAW format. ‘IIQ Raw L’ is set as the default and is the lossless capture format of the P+ back. IIQ Raw S’ is a smaller file, and not totally lossless in the format. The ‘IIQ Raw L’ is approximately half file size of the processed TIFF file. ‘IIQ Raw S’ is approximately one third of the processed TIFF.
12 For further information, see
13 For further information about Adobe Photoshop, see
14 For further information, see
15 For further information, see
16 For further information, see
17 Tyvek is a synthetic material consisting of heat-fixed fibres of HDPE (high-density polyethylene). It is impervious but vapour permeable. In other words, it breathes better and this is good for the timber. For further information, see

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