Invented from CopiesInvented from Copies

Due to its white background, the whiteprint was ideal for adding changes, annotations and colour schemes. This created dialogues on the copies between clients and architects. Such exchanges of ideas made whiteprinting a vital link in the design process. In this essay, curator and archivist Clara Stille-Haardt discusses the whiteprint's peculiarities and significance based on examples from the National Collection.

A whiteprint is a type of print in which the background is white and the lines are coloured. The diazotype is a specific technique of whiteprinting. Both are forms of photoreproductive prints, an umbrella term for a copying process that requires natural or artificial light to make a copy. How did the whiteprint, and later the diazotype, gain a foothold in architectural design practice in the early 20th century? The wide variety of whiteprint techniques in circulation during the experimental phase of this copying method particularly calls for closer examination. How has this technique been incorporated into the National Collection for Dutch Architecture and Urban Planning at Het Nieuwe Instituut, what is the status of these copies, and how are they appraised? Are these copies, by definition, codas to the design process or the starting point in a new design phase? Did this copying method quietly die out with the introduction of the electrostatic copying machine in the late 1960s, or did this technique bridge the gap to digital design? And how does contemporary artistic design practice regard this reproduction method?

Architect J.J.P. Oud's design dossier for the Spaarbank's new office on Botersloot in Rotterdam (1942) contains a surprising number of whiteprints of, among other things, a round façade ornament. The post-war reconstruction period saw a boom in building activity, and whiteprinting's growing popularity runs parallel to this. This series demonstrates how whiteprinting gradually acquired an essential role in all phases of the design process and, above all, how it became a vital instrument in the culture of consultation between architect and client. The possibility to make copies effortlessly made it easy to continue working by adding a new layer of ideas, changes or colour schemes. A copy would thus become a new 'original'.

Even though the analogue copying process gave way in the 1980s to the copier, plotters, computers and advanced software programs, experiments with whiteprinting continued in contemporary artistic practice. Set designer Hans Christiaan van Langeveld used whiteprints to draw his designs and made collages from tracing paper (transparencies) to replicate them into set designs. He placed two sheets of tracing paper on top of each other to allow less light to pass through, creating a dark print with several uniformly grey areas that he then painted over with Indian ink. In this way Van Langeveld created a wealth of grey tones, infusing his set drawings with depth and texture. Liselotte Doeswijk. (2017, 11 Jan.) Tekenen met de lichtdrukmachine. Vorm van vermaak. https://vormvanvermaak.nl/tekenen-met-de-lichtdrukmachine/

Contemporary artists also have an interest in researching and experimenting with whiteprinting. In the Ozalid project from 2002, a group of visual artists edited a collection of folded whiteprints, presenting them in a flat box bearing the Ozalid diazotype brand name. Liesbeth Doornbosch's paintings and collages feature cut-up whiteprints of buildings that she rearranges to create new transparent compositions. American artist Francesca Woodman exhibited life-sized collages made from diazotypes at the Guggenheim Museum in New York. Woodman's work prompted a study and article by the American Institute for Conservation of Historic and Artistic Works. Woodman's experiment with the diazotype and other artists working with this copying technique pose conservation challenges relevant to the collection of whiteprints in the National Collection at Het Nieuwe Instituut.

After an initial survey of whiteprinting and later of diazotypes from 1923 onwards in the National Collection at Het Nieuwe Instituut, it became clear that the overwhelming number of copies and the diversity of whiteprinting techniques would pose a significant challenge for this research. The search for the oldest whiteprint confirmed this once again and gave us cause first to take a critical look at the whiteprint's origins.

The second half of the 19th century saw much experimentation with photoreproduction techniques. The blueprint's introduction brought new possibilities for the reproduction of construction drawings. However, there was an increasing demand for a more stable and efficient copying technique that gave a positive print of black lines on a white background. Architect P.A. Frylink wrote about the production of whiteprints in the Bouwkundig Weekblad as early as 1890, pointing out this was due to increasing demand from the building industry. Manufacturers and architects wanted a copying technique that gave a positive image. Two decades later, this became a reality. Architect J. Duiker mentions this in his notes during the construction of the Rijksacademie in Amsterdam in 1917: 'The contractor produces traced copies on transparencies to the satisfaction of the management. The contractor also supplies two sets of photoreproduction prints (black lines on a white ground) of each of these transparencies. One set is for the contractor's use, the other for the management's use.' Inventory DUIK 3.2, Collection Het Nieuwe Instituut.

Frylink describes the four phases of making a whiteprint. The paper was first prepared with a photosensitive ferrous sulphate and exposed to light under the original in a printing frame. The image was then developed in a flat tray with gallic acid. After one to two minutes, the copy was removed from the bath, and the excess salts were washed away. It was possible to make the paper light-sensitive, but prepared paper was also available and called Colas paper, named after its inventor. The prepared paper had a bright yellow tint, which turned white when exposed to light. Frylink mentions that the advantage of the whiteprint is it can be easily retouched and coloured. This technique was initially laborious, and it was challenging to achieve a pure white background, which tended to remain more or less violet.

Reference books on preserving photomechanical reproductions describe the different whiteprinting techniques in more detail. From 1850 until the introduction of the diazotype in 1923, considerable experimentation took place to achieve a faithful copy of an original drawing. The most common whiteprinting techniques were the Ferro-Gallic print (1859), the Aniline print (1864-1890) and the Van Dyke brown print (1889-1960).

Despite these innovations and the variety of possibilities for making positive copies showing clear, fine lines in different colours, the processes were laborious. This period of experimentation failed to reduce printing costs since it took several reproduction devices to make a high-quality copy. The development of a more stable and efficient copying method was needed to market this technique and respond to growth in the building industry.

The diazotype's origins lie in the development of synthetic dyes for the textile industry. In 1890, a diazo technique called the diazo primulin process was first used for transferring a duplicate onto textiles. The English chemist Arthur Green (1864-1941) published his discovery and explained how images could be transferred to linen, silk and wool via a derivative of primulin dye. Green also mentions the possibilities of printing leaves, flowers, ferns and insects on textiles sensitised by diazo primulin.

Besides the textile industry, there were also experiments in diazo technology for photographic processes. Anthony's Photographic Bulletin published the first article on the subject in 1885. Meanwhile, there was vigorous experimentation to perfect diazo type processes for design purposes. The early 20th century saw the emergence of new technological developments and increased building activity; thus, the demand for a fast and efficient copying process became increasingly urgent. The German firm Kalle & Co (later Ozalid) and the Dutch firm Van Grinten (later Océ) seized this opportunity and developed a new copying formula: the diazotype.

Like the whiteprint, the diazotype process gives a positive print but uses different chemicals. It came onto the market in 1923 and required treating paper with a two-component solution of diazonium and azo to make it light-sensitive. After exposure to light and ammonia vapours, an image formed of diazonium dye appears on the paper. This dye is not in the paper fibres, as with the blueprint, but lies on the paper. As well as being a positive image, the diazotype also had the benefit of providing a clear image and the ability to retouch, and it was relatively inexpensive. It was also a dry application which prevented the copy from shrinking and kept the design's scale stable.

How exactly is a diazotype made? The drawn side of a transparency is placed on a paper photo-sensitised by diazonium and then exposed to ultraviolet light. After a fifteen-second to five-minute exposure, ammonia vapours transfer the image to the photosensitive paper. Diazotype lines are usually black and brown, but sometimes they are purple, blue, red or green, and the background is also sensitive to variations in colour. The characteristic yellow-brown colour is only present on the front side, which has been made photosensitive. The yellowing is usually pronounced at a diazotype's edges because that is where the photosensitive layer stops. Ozalid brand diazotypes have a pale rusty brown background and brown-red lines, and sometimes the paper has a watermark or a small round logo. The introduction of this new duplication technique was a crucial step in the development of copying. The diazotype method was essential for the production of countless copies for nearly 70 years. Therefore, it is not surprising that perhaps half of all drawings in the National Collection at Het Nieuwe Instituut consist of copies or documents intended to be duplicated.

Following the adage that 'a good technical drawing is the foundation of a good product', architects, engineers and the aviation industry quickly recognised the advantages and the popularity of the diazo process. The Dutch company L. van der Grinten Chemische Fabriek saw the success of Kalle (later Ozalid) as a threat to its blueprint production and decided in 1927 to improve upon Kalle's diazo process. Kalle's advantage was that it was a dry method, but the prints quickly turned yellow. Van der Grinten, therefore, developed the primulin semi-wet process, which made the copies less yellow. A battle ensued with Kalle over the patents. Eventually, Van der Grinten brought the O.C. (abbreviation for Ohne Componente) copy paper onto the market, later adding an 'é' to the name to become Océ.

The chemically treated paper was first exposed in the copier, and then another liquid was added for development. This anti-yellowing method made a significant advance in the development of the diazotype. P.C.P. Huysers describes the diazotype technique in more detail in his 1938 article 'Diazotype and reflectography'. He explains the diazotype can usually be printed on paper and other materials such as transparent paper, film and linen. Engineers and architects mainly used the diazotype for copying technical drawings. The reproduction of written documents was introduced in 1936, making the diazotype an effective tool for office administration, advertising and graphic design. Huysers pointed out that better and faster equipment was also being developed for making diazotypes, ensuring that making copies was for both a small, specialised set of users and a broader target group.

This democratisation of the copying culture led to a surge in diazotype technology and the production of copies. The companies Ozalid and Océ put the diazotype on the map worldwide and extended their international reach. They were widely represented in the former Dutch East Indies, where they had several sales outlets, advertised in newspapers and participated in trade fairs. The ease of copying and the possibility to make diazotypes on lightweight paper ensured this copying technique was used internationally as a communication medium.

The importance and professionalisation of photoreproduction companies also played an essential role in the development of copying, particularly the growing use of diazotypes. With the advent of photoreproduction at the end of the 19th century, architects and engineers could more easily outsource photoreproduction printing. It was possible to place orders for whiteprints and blueprints on various paper sizes, and the photoreproduction company would take care of the handling. Even with the introduction of the diazotype, the subcontracting of duplication processes remained an attractive option for architectural firms. Several archives in the National Collection at Het Nieuwe Instituut contain invoices and correspondence between architects and photoreproduction printers. For example, the archive of Albert Boeken contains noteworthy invoices from the Rynja Photoreproduction Company from 1943 to 1951 that distinguish between 'whiteprinting' and 'Océ printing'. The latter was ten cents more expensive. Inventory BOEK d238, Collection Het Nieuwe Instituut. They probably made their own formula whiteprints and were thus cheaper than Océ prints.

Pieter Liskes Rynja founded the Rynja Photoreproduction Company (Lichtdrukkerij Rynja) in 1892. He worked as a supervisor at the office of P.J.H. Cuypers and foresaw the copying process would take off among architects. Rynja often advertised his photoreproduction company and had an extensive network of customers, including the Van Gendt brothers, L. Springer, H.P. Berlage, the State Telegraphy Office, the Amsterdam Service for Public Works and the Kromhout engineering factory. The company's courier service had a car and bikes for delivering drawings and photoreproduction prints to customers. Rynja also became one of the first buyers of Océ's photoreproduction paper. Rynja had excellent brand recognition and was known for its quality by trade colleagues and architects. In the archive of architect M. Duintjer is a diazotype bearing this photoreproduction company's watermark. The network of photoreproduction companies also included Wed. J. Ahrend & Son (now Royal Ahrend), which also had a reproduction facility.

The product catalogues in the Océ company archive demonstrate they were focusing all their efforts on developing the diazotype and associated copying machines. The reports and product catalogues also show they were increasingly investing time and money in expanding the sales market and further developing the technology. For example, they created an odourless liquid to replace ammonia vapour and focused on making the copying process more efficient and increasing the processing speed. They also experimented with diazotype compounds, light source stability and light sensitivity. In the 1950s, diazotype copiers were on the market that produced up to 300 diazotypes per hour. Diazotype paper was available in 60, 80, 110, 150 and 210 gsm, from A5 to A0, and 500-metre rolls.

These advances created new opportunities for architects and designers. The copy became a vital part of a design system and allowed for actively sharing duplicated drawings during all stages of the design process.

A circular from 1931 in the Océ company archives refers to the importance of the original transparency. If stored carefully and copied onto Océ Acute transparency paper (this was called the duplicate original), it was possible to continue copying with them. An erasing knife could remove drawn lines on the back of the acute transparency, making it possible to create completely updated versions from old or damaged earlier generations.

If a design had to be sent to clients or associated parties, it was practical to send a duplicate original for them to make any number of prints. It was possible to produce different combinations of originals by assembling items from old and duplicate originals. The results did not show that they were composites. Océ said acutes had an almost unlimited shelf life with no loss of quality.

This copying technique caused an overproduction of diazotypes in architectural design practice, which is also evident in the collection of Het Nieuwe Instituut. Since the 1940s, acute transparencies have been increasingly used, especially for large assignments involving several parties. J.J.P. Oud, for example, used acute transparencies for developing the façade ornament of the Spaarbank on Botersloot in Rotterdam (1942).

The research into the Océ company archive provides valuable information about this experimental phase of the diazotype and its use in design practice. Many possibilities arose from the development of double-sided diazo paper, Océ colour developer, and extra-thick diazotype paper that allowed designers to experiment with colouring diazotypes using watercolours and the like, giving copies an artistic quality. Diazotypes could also be printed onto polyester, making them less vulnerable to tearing. They were often used for city and district plans, electrical diagrams, organisational charts, and documents requiring frequent consultation. Various devices for processing diazotypes were available for drawing offices, from smaller architectural firms that processed 2000sqM of diazo paper per year to large project offices that used more than 20,000sqM of diazo paper annually. These fully automated photoreproduction machines could print, cut, and fold the copies.

The diazotype is not immediately recognisable from a striking Prussian blue colour or a glossy surface; thus, it can be difficult to discern. The diazotype's resemblance to the 'original' hand-rendered drawing, the variety of paper types used, the exposure intensity, their large quantities and colour processing make it an interesting but hard to identify medium. The amount of diazotypes in the National Collection at Het Nieuwe Instituut is an important reason to investigate the significance and appreciation of this copying technique. Given the diazotype's influence on design culture for more than seventy years, what should its position be in the National Collection?

An invaluable means for identifying diazotypes in the collection is recognising specific features and ascertaining their characteristics through a close reading of the line colour, exposure, background colour, paper thickness, the back of the drawing and any signatures, watermarks or additions such as notes and colouring techniques. Before Ozalid and Océ brought the diazotype to market, there was an intervening period of experiments with various whiteprinting techniques. It is imperative to include this period in this research because it was a starting point for copies with a positive image and a catalyst for the diazotype's development.

The oldest pre-diazotype whiteprints are in the archives of P.J.H. Cuypers, the office archive of Cuypers, Architectenbureau van Gendt en Zn., H.P. Berlage, J.J. and M.A. van Nieukerken, W. Kromhout and K.P.C. de Bazel. The archive of K.P.C. de Bazel contains early whiteprints in the dossier for a doctor's house at the Meerenberg Psychiatric Hospital in Bloemendaal (1914). These whiteprints were made on thin paper bearing an 'M.L. & Co.' watermark. Their light-grey background is grainy and low contrast, rudimentary identifiers of early whiteprints.

Ascertaining a whiteprint's date requires some research because its production does not always match the design's original date. The date on the hand-drawn earlier version of the design drawing was usually also copied. This can often be seen in copies for restoration projects, such as in the archives of J.J.P. Cuypers. The early whiteprints of Cuypers' renovation design for the Senate of the Netherlands from 1909 show that this is a copy of a design drawing from 1888.

While looking for the oldest whiteprints in the collection, we noticed that photolithographs were also popular in the period of experimental whiteprints. They also have black lines on a white background and closely resemble whiteprints, which can be misleading, but they use a different copying process. Wegner & Mottu in Amsterdam often produced photolithographs. Compared to early whiteprints, the lines were much sharper and the background was evenly white. These lithographs were usually made for publishing construction drawings in trade journals. The process lent itself well to reproducing multiple equivalent prints. H.P. Berlage had his presentation drawings for the Merchants Exchange in Amsterdam lithographed by Wegner & Mottu.

Despite the introduction of diazotypes, architects used blueprints well into the 1950s, probably because the diazotype was still a laborious process and the chemicals were more expensive than for blueprinting. Convenience may also have played a role. Architects liked using the equipment they had and with which they were familiar. Another reason could be the diazotype was sensitive to dirt (due to the light background) and was preferably not used on construction sites. Legislation and regulation requirements also played a considerable role in the continued use of blueprints. Architects and structural engineers often had to supply a set of blueprints and a set of whiteprints when applying for a building permit. Invoices in the archive of Amsterdam architect A. Boeken from 1943 show that he had his photoreproduction prints made at P. Rynja photoreproduction printing company. At that time, blueprints were still 10 cents cheaper than Océ prints (diazotypes). They may have made both types of photoreproduction print (positive and negative images) to increase the drawing's legibility.

Sometimes, a design drawing would combine a diazotype and blueprint. For example, G. Rietveld cut plans from diazotypes and pasted them onto a blueprint, creating a mixture of photoreproduction printing processes. It is unclear why Rietveld did this, but perhaps it was a quick way to make changes or for emphasis. He also provided the plans with notes and directions in colour. In the 1923 handbook, De practijk van het werktuigkundig en electrotechnisch teekenen (The Practice of Mechanical and Electrical Drawing), Swierstra writes about the use of whiteprints and blueprints: "Not only should whiteprints preferably be treated with clean water, but it is also important not to rinse whiteprints and blueprints in the same container unless the container is always cleaned properly. The water rinsed off of blueprints will leave blue spots on the whiteprints, while the lines of the blueprints will become less clear." Swierstra, R., De practijk van het werktuigkundig en electrotechnisch teekenen [The Practice of Mechanical and Electrotechnical Drawing], 1923. The copies in the archive of architect H.J. Jesse demonstrate that these processes were used in close conjunction.

The collection features the diazotype in all phases of the design process, from sketch to presentation drawing, and at all scale levels, such as urban development schemes, interior and landscape designs and constructional components. Because of the diazotype's ease of use and low production costs, graphic designers used them for preparing presentation books. The numerous diazotypes in the collection reveal how designers would develop a signature style of working and reproduction methods. Were these from material consideration, artistic expression or purely out of convenience? Large agencies such as Van den Broek and Bakema often had extensive assignments and, therefore, a high output of copies to work with third parties. They developed a copying system in which the diazotype became a vital communication hub. The archives of G. Rietveld and T. Wijdeveld show they used the diazotype to aid in designing and communicating with the client.

Besides the fact that the diazotype lent itself well to making changes and taking notes, the most significant advantage was that applied colours would be clearly visible on the white background. All phases of the design process used colour, such as technical support for explaining colour schemes and legends for installation drawings, heating systems, sewage systems, water pipes and electrical diagrams. A design by Van Nieukerken illustrates how the legend corresponds to the construction of a garden at the Dutch sanatorium in Davos, Switzerland (1937). Wijdeveld made a decoration scheme for a tile floor in the shop of the SS Nieuw Amsterdam passenger ship. The diazotype was also used as a template for designing and visualising decorative patterns of tiles and the like and emphasising or imitating material properties. Van Gendt coloured diazotypes with ink and watercolour to illustrate a Mauro tiled floor. E. Cuypers made diazotypes of charcoal drawings and used pastels to embellish them with an Indonesian atmosphere.

The diazotype was also a document for elaborating on decoration schemes or making interior studies, such as Pi de Bruijn's redesign of the House of Representatives in The Hague. The use of colour on copies served to convince clients and explain a system. Besides such practicalities, applying colour helped paint an artistic impression, visualise how colour affects a space, and emphasise material properties such as wood grains or metal (using metallic paint).

The diazotype's white background made it ideal for adding new layers of information. Its ease of reproduction meant that work often continued on duplicates, which were then copied again, creating a dialogue on the copies between client and architect. Because of this exchange of ideas and opinions, copies became an increasingly important conveyor of meaning in the design process. The copies in D. Greiner's project dossier for houses in Betondorp demonstrate how they allowed him to communicate with the client, Amsterdam's Municipal Housing Service. Copies made it possible to coordinate wishes and proposals. The archives of Rietveld, Theo van Doesburg, Brinkman and Van der Vlugt, Jan Verhoeven and Wijdeveld also contain noteworthy examples of diazotypes that have notes and played a key role in communicating the use of colour in the design process.

The diazotype's use continued well into the 1980s. Despite the introduction of the commercial photocopier in 1949, architects continued to work with the diazotype for a long time. There are several reasons for this. Firstly, convenience. As with the introduction of the blueprint and the transition to the whiteprint, the diazotype had teething problems and required investment in new machines and learning to operate them. Larger architectural firms often had a photoreproduction machine. A 1980 manual on architectural drawing states that architects and drafting technicians are often wary of new drawing and reproduction methods because they do not like to deviate from their usual working methods. The perceived risks concerned the increase in time and poor results, and they did not want to just give up an essential part of their knowledge, skills and expertise. In addition, there was still no alternative to digital drawing. The AutoCAD program's use was not widespread until the mid-1980s.

The studies into the literature, the Océ company archive and the close reading of diazotypes have increased the knowledge about this influential copying process and showed how this technology is embedded in the project files of designers in the National Collection at Het Nieuwe Instituut. This research is also a first step toward questioning the status and appraisal of the number of copies in the National Collection. In particular, the efficiency gains made through the diazotype's development and commercialisation have considerably influenced the spread of the copying system among designers. Alongside these insights, the traces visible on diazotypes tell a granular story about the copy's role in the design process and the management and preservation of these copies. The follow-up study on the diazotype will also focus on the role of the copy as a consultation document and the use of colour within the copying system.