Pre-publication Invented from Copies: Osaka 1970Pre-publication Invented from Copies: Osaka 1970

Invented from Copies: Blueprints, Whiteprints, Zips and Photocopies in the Architectural Office, 1870-2000 is a publication by the Nieuwe Instituut in collaboration with nai010 publishers.

From its conception in 1968, Jan Cals’ vision for the Dutch Pavilion at the Expo was clear: to showcase the Netherlands as a modern nation, both economically and culturally. Cals knew that Japan was set to invest 100 billion dollars in the European economy between 1968 and 1980, so it was crucial to present the Netherlands as a contemporary gateway to Europe. Alongside this economic vision came a new cultural impetus for the pavilion.1 Rather than displaying physical objects and products, as was customary, the exhibition would tell a story about the Netherlands from historical and contemporary perspectives through reproductions. Visitors would be transported by escalators into an immersive kaleidoscopic spectacle of simultaneous film projections on multiple 3.5 by 6.5 metre screens and synchronized slide projections behind mirror film in the hall of mirrors, accompanied by sounds such as children’s laughter and airplane noise. Two reflection rooms designed by Peter Struycken were a multimedia highlight. Here, visitors could relive the film on the mirrored surfaces on the walls, ceiling and floors, arranged by Struycken using a computer. In short, a continuous stream of reproductions of traffic, activity, recreation, art, judo, nature and daily life presented the Netherlands as a modern cultural equivalent of Japan.

In order to provide this new cultural impetus, Cals commissioned Jaap Bakema to design the pavilion, alongside two promising young architects: Piet Blom, winner of the Prix de Rome in 1962, and Carel Weeber, winner in 1966. However, Blom declined to collaborate, as Osaka was too far away! This left Weeber and Bakema. Other progressive designers and artists joined Weeber too, including filmmaker Jan Vrijman and graphic designer Wim Crouwel, who shaped the design and programme.

Bakema already had an impressive track record when he began work on the pavilion. In his 1955 exhibition designs for E55, the Dutch national energy exhibition about the reconstruction of Rotterdam (1955), and the Dutch pavilion at the World’s Fair in Brussels (1958), as well as his television series Van stoel tot stad (1962 – 1963), he had demonstrated his ability to engage a wide audience with compelling narratives. Bakema had extensive international experience and was the co-director and figurehead of one of the largest and bestknown architectural firms in the Netherlands. With around 200 employees working in various design teams, the office took on a variety of large-scale commissions for buildings, residential areas, expansion plans and city centres, both domestically and internationally. The firm operated like a well-oiled machine, handling both the design and execution of projects. Each team included designers, draftsmen, cost estimators, specifiers and supervisors. There were also separate departments for administration, specifications and budgets, construction department and visualization – the latter producing perspective drawings, photographs, films, texts and publications. In order to handle the large volume of orders, the firm was highly skilled in working with copying system of the time, which consisted of master tracings, sepia diazotypes and whiteprints, as well as Zips. The production of whiteprints and sepia diazotypes was outsourced to the Lichtdrukkerij Rotterdam, located downstairs from the office, or to the photoreproductive printer Ahrend, which was located further away.

In 1969, Weeber, at only 30 years old, was part of the younger generation. Unlike Bakema, he did not have his own architectural firm. Prior to graduating, he had worked at Ernest Groosman’s firm and possibly worked from his apartment in Capelle aan den IJssel, where he was living when he designed the Osaka project. At Groosman and in his design for the Prix de Rome, Weeber developed a particular approach to architecture. Rather than arriving at a unique design for a specific location through sketching and drawing, he approached architecture through the application of geometry, measurement systems and typology.

At just over two years, the time for design and construction was short. The concept, programme, execution and interior design had to be finalized during this period. This required efficient and concise communication. The numerous reproductions of the design indicate that communication between the Dutch and Japanese stakeholders mainly took place through these reproductions. Furthermore, various parties contributed. In May 1968, Weeber and Bakema contacted Masachika Murata’s firm in Tokyo, where architect Masahiro Murata would oversee the design, tendering and construction in Japan. In the Netherlands, structural engineer J. Kromhout was brought in to work alongside Weeber on the design of the structure.

In September 1968, Bakema and Weeber travelled to Japan to consult with Murata. Following this trip, the design team was expanded to include other Japanese stakeholders, including the structural engineer and consultant Fugako Yokoyama and the contractors P. Morimura and Takenaka Komuten Ltd., based in Osaka. A division of labour was established. The architects were responsible for providing written specifications, detailed drawings, principle details and material specifications. The contractors created all the working drawings, which the architects then reviewed. If necessary, the Japanese contractor would adjust these drawings prior to construction.

Communication between the Netherlands and Japan involved crossing a distance of approximately 10,000 kilometres. Many reproductions of designs were sent by mail and were probably also taken on the plane. Questions and comments were sent by letter and, if necessary, by express mail or telegram. As Weeber was more involved in daily operations than Bakema during the process, he flew back and forth 12 times, spending extended periods in the Kobe area and at Murata’s architectural office. In contrast, Bakema only travelled to Japan occasionally for consultations. To facilitate knowledge transfer, the Japanese architect compiled albums of photoreproductive prints of the construction and execution drawings for the Dutch architects and structural engineers and the Japanese actors involved in the design and construction. This method forms part of a Japanese tradition of binding working, construction and execution drawings together in a book to ensure a complete set. The format is always vertical and the pages are glued together at the edges. In this case, the Japanese texts have been adapted to Western left-to-right notation.

In September 1968, Bakema and Weeber visited Murata, carrying reproductions of a well-developed design probably produced at the Van den Broek en Bakema office. These reproductions were used to discuss the architectural concept in terms of execution, financial feasibility, construction and legislation. Using blue Zips, the design was developed on a transparent sheet and then reproduced, revealing its striking plasticity. This plasticity was reminiscent of Bakema’s unrealized design for the Euromast in Rotterdam from 1957. This 80-metre-high tower consisted of four rotating, cantilevered pavilions at different heights. Bakema intended to replicate this design for the Osaka Pavilion. However, practical and conceptual obstacles hindered its realization. Nevertheless, the concept of rotating and cantilevered cabins surrounding a tower remains a tangible experience, albeit only 32 metres high. A series of sepia diazotypes showcases these sculptural qualities as shadow – a feature that was also necessary in Osaka’s warm climate. A top view of the exterior reveals light blue Zip film for the pond and dark blue for the shadows on the ground level. A second sepia diazotype shows that this sheet of film was used for reproduction and also shows two different shades of grey, with the dark grey, almost black, further emphasizing the rendering of shadows. In the margin of the sheet is a pencil note, probably made during a meeting: ‘With shadow and snack bar’, which is also visualized in a sketch.

Aside from the conceptual connection between the content and the visualization method, these Zip film reproductions were consistent with the working methods of the architectural firm Van den Broek en Bakema. The material was readily available and purchased wholesale, and the office also had expertise in working with it. Like other architecture offices, Van den Broek en Bakema used Zips because they accelerated the design process, their transparency allowed for copying and produced a smooth print and background, giving the visualization a contemporary feel. Van den Broek en Bakema also used Zips to create specific spatial accents or emphasize plasticity. This required extensive knowledge and experience of the material.

Zips were used for effect after reproduction, when it was important for the visual impact to reinforce the message of the design. A sepia diazotype of the design, dated 9 September 1968, captures its essence. Prior to this, the design was drawn on a transparent sheet and the darker portion was covered with coloured transparent film. This transparent sheet was copied using the photoreproductive process to create a reproduction with the desired effect: a giant cinema comprising continuous dark spaces within a black-and-blue interior. This emphasizes the pavilion’s main function of multimedia presentations in the form of film and slide projections in an interior with no daylight.

The colours of Zips often form a secret code. You can only decipher them if you know the codes. The transparent sheet below only reveals its true colours when reproduced in a whiteprint. These films are then transformed into a specific shade of grey, which corresponds to the actual colours of the interior. The ‘blue’ carpet becomes light grey after reproduction. Yellow becomes dark grey, making it suitable for displaying fixed architectural elements such as walls. Experienced architects knew this secret code by heart, but less experienced designers could refer to a checklist provided by Zip-A-Tone manufacturers that indicated which colour produced which specific shade of grey in reproduction, ranging from very light to very dark (see the Zip-A-Tone colour wheel in the chapter ‘Zips! 1945–2000’).

Several sepia diazotypes of the design reveal another one of Weeber’s preoccupations: the need to work with a system of measurement. As well as being a characteristic of Weeber’s design method, in the case of Osaka it added an extra advan- tage due to the short design and construction time, as well as the collaboration with a Japanese contractor, architect and structural engineer. Systematic designs based on a measurement system contributed to clear communication and prevented surprises during execution and on-site work. Basic sheets with the measurement systems were created for copying the design, enabling a portion of it to be represented according to the same system.

The Osaka design file shows that sepia diazotypes with Zips were ideal for making adjustments to the design. The sepia diazotype of the southeast façade shows the changes made to the design. The viewing windows have been removed and the rectangular window frames have been changed to have rounded corners. Existing lines were scratched away to make corrections. This process removed the sepia diazotype coating, leaving white areas. Then, the black lines of the window frames with semi-circular corners were drawn in. The sepia diazotype was then covered with blue film. After reproducing the sepia diazotype using the photoreproductive printing process, the corrected lines were invisible, leaving only the new design visible. The window with rounded corners, acting as a ‘TV screen’, became the logo of the Expo pavilion. This format was used for all printed materials and advertising.

As well as being used for copying processes, Zips also served to visualize the actual colours and sheen. Three reproductions demonstrate how the use of colour contributed to the pavilion’s distinctive character and highlight Weeber’s pivotal role in its development. In consultation with Sia Bakema, the colour consultant and wife of Jaap Bakema, he proposed a colour scheme of orange, blue and silver-grey. These colours were applied as autonomous bands across the asbestos panels on the façades, arranged in the shape of a Greek cross. The blue referred to the Netherlands being below sea level and the orange to Dutch identity, while the silver gave the pavilion a futuristic and light appearance.

Weeber presented his colour design at an exhibition of his work at the Netherlands Architecture Institute in 1990. He used a black-and-white visualization by Robbert Das from 1968, which was published in Bouw that same year. The accompanying text from 1968 stated that ‘the exterior is covered with flat asbestos sheets, which will be painted in bright colours’. Therefore, the precise colour scheme of blue, orange and silver was not known at that time. It is likely that Weeber adapted this illustration with coloured foil, to present the actual colours at the exhibition, only in 1990. He may have done the same with two diazotypes of the façade designs from 1968–1970. The orange and blue Zips applied in 1990 depict the mirrored effect of the exterior. The grey gridded Zips, some of which are positioned beneath the blue and orange Zips, emphasize the pavilion’s plasticity.

Invented from Copies has been made possible with the support of the J.E. Jurriaanse Foundation and Koninklijke Rijnja B.V.
The book will be available from 27 November 2025 at NAi Booksellers.