Earlier archive edits
The first editing of the Cuypers archive was initiated by the Amsterdam professors C. Peeters and C.A. van Swigchem. For this purpose, the archive was transferred to the library and documentation center of the Catholic University (KDC) in Nijmegen in 1969. The archive to be processed consisted of two parts. Part A (see above) came from the RDMZ and consisted of 15 crates with bundles of drawings, 13 large and medium-sized portfolios and various plate works. Part B (see above) came from the Cuypers depot at the Rijksmuseum and was stored in 25 laundry baskets, 8 large portfolios, 20 large sliding members and also contained loose material. In addition to items from the Rijksmuseum file described in this inventory, this part included the archives of the architects K.P.C. de Bazel and J.J., M.A. and J. van Nieukerken.
Both parts of the archives (A and B) were edited by students F. Asselbergs and H. van Crimpen from 1969 to 1971. The first access, consisting of fiche cards, dates from that time. The cards were made at the time with the intention of providing a standard description of all projects present in the archive. The following information was noted on the fiche cards: location, type of building, type of assignment, client, date and architect. Then it was checked which projects were found to have drawings, correspondence and documentation. Then the numbers of the packages were also noted on the cards. These numbers have since functioned as application numbers. The maps were organized in various ways: by topography, by building type, by year and by folder number. Drawings by other architects were also described in a separate catalog. The card bins could thus be used as access to the archive until 1991.
However, the archival editing by Asselbergs and Van Crimpen was never fully completed. Not all of the material was described on the fiche cards and non-project-related material was not described at all. After editing, the archive moved from Nijmegen to Amsterdam in 1971, where it was managed by the NDB. A part containing mainly person-related material remained with Asselbergs for study and was added to the rest of the archive in 1992 and described globally as a supplement.
When the NAI was established in 1988, the archive was prepared for its move to Rotterdam. To this end, the various parts of the archive were given codes: CUYP, CUYX and CUCO.
The archive of P.J.H. (Pierre) Cuypers with code CUYP concerned the bureau archives of Roermond and Amsterdam with a size of about 250 linear meters. In 1993, the fiche cards arranged by topography in the card index were used as the basis for an inventory. This topographical access consisted of six ring binders:
Part I: Correspondence and photographic plates;
Part II a + b: Drafts (drawings); Supplements (miscellaneous; particularly unordered part of the archive);
Part III: Negatives;
Appendix I: Further accesses to the Rijksmuseum file in Amsterdam;
Appendix II: Further accesses to the file of De Haar Castle in Haarzuilens; Indexes: Indices by toponym and keyword on the copybooks (both general and those of the Rijksmuseum); List of chiefs of the art workshop; Inventory of Cuypers' bookstore.
The archive of J.Th.J. (Joseph) Cuypers with code CUYX, dated from 1880 to 1958 and measuring approximately 12 linear meters, covered only a portion of the entire archive formed by Joseph. The vast majority of his archives were in CUYP because of the collaboration with his father. CUYX also contained the archives of P.J.J.M. Cuypers, Joseph Cuypers' son.
The archive of art workshop Cuypers, Stoltzenberg and Co. with code CUCO, included about 150 linear meters and was dated from 1852 to 1907.
In 1992, the temporary collection of archival negatives and slides with code CAND was formed at the NAI. This housed 293 glass negatives originating from CUYX and 564 glass negatives originating from CUCO.

Re-inventory of the Cuypers archive
The Cuypers archive was accessible and consultable. In practice, however, consultation proved difficult for (scientific) researchers, (restoration) architects, exhibition makers and the interested NAI reading room visitor. Factors that made consulting the archives difficult were: the size of the (sub)archives and files; the accesses were imprecise, incomplete and often incorrect; material documenting a single project was located in different sub-collections; the non-project-related material was not described, nor were the acquisitions made after 1973; the original serial character of the drawings and written documents was no longer intact; material by other architects had entered the archive in the past; the material condition of large parts of the archive was poor, consultation and availability were therefore in many cases actually irresponsible.
It was expected that the demand for a clear and responsible inventory would increase in the near future. This was prompted in part by the remodeling and restoration of two of Cuypers' largest projects: the Rijksmuseum in Amsterdam and De Haar Castle in Haarzuilens, and the related scientific and architectural investigations. There was also hope that a proper inventory on the colossal archive might contribute to a monograph that was still missing. The significance of nineteenth-century architecture had been emphasized in previous publications. Study of the source material could enhance the quality of the debate about it.
In view of the state of the archives, the quality of the entries and the need for a good inventory, it was decided in 2000 to start working on the Cuypers archive again. It began with the inventories of the building file of De Haar Castle (code HAAR) and that of the Rijksmuseum (code RYKS). These two inventories were completed in 2001 and 2002, respectively. The Rijksdienst voor de Monumentenzorg largely financed the first inventory. Funding for the inventory and conservation/restoration of the Rijksmuseum file was provided by the National Building Service.
In 2002, the Getty Grant Program of the Getty Center of Los Angeles awarded a grant to the NAI for the inventory of the remaining Cuypers archive. This editing began in 2003. First, the Central Station file - Cuypers' third major project (code CENT) - was taken up. After that, work began on the Cuypers Bureau Archive (code CUBA) and the archive of the Cuypers Workshop (code CUCO). Finally, the personal documents were inventoried (code CUYP), including the extensive photo archive. At the end of 2007, the entire project could be completed.
The files of Kasteel De Haar, the Rijksmuseum and Centraal Station in Amsterdam are of course part of Cuypers' office archive, but the files have been described in separate inventories because of their size and complexity.

Bureau archive/personal archives.
In the archives of P.J.H. Cuypers and his son J.Th.J. Cuypers, both material documenting projects of both of them was found, as well as material documenting their personal lives and the activities related to their professional lives. The choice to separate the project-related material from the person-related material was obvious.
The person-related archives of both architects (CUYP) includes personal correspondence, correspondence with contemporaries and peers, sketch and notebooks, travel sketches, diplomas and awards, collected photographs, etc. The office archive (CUBA) is the record of the actions of the Cuypers architectural firm.

Family firm
During the preliminary research into the project-related archives, it soon became apparent that many projects had been worked on in different years. For example, P.J.H. Cuypers began the construction of a church, his son J.Th.J. Cuypers later took care of the extension and refurbishment of the church, and still later J.Th.J. Cuypers in collaboration with his son P.J.J.M. Cuypers restored the facade, for example. A project remained in the family for sixty years, as it were.
It was obvious to document such a project in all its facets with all available material. To this end, material concerning the project that had been housed in the various archives of father and son during a previous operation was lifted and placed in the Cuypers' office archive. During the inventory, it was considered important to make the development of the architectural firm's oeuvre and organization visible in the arrangement of the project-related archives. This idea took shape thanks to the knowledge acquired during the inventories of the top projects and the progressive insight into the oeuvre, working methods and organization of the architectural firm. With a chronological arrangement of the project-related material, the inventory would give a good picture of Cuypers' organizational ability to cope with the constant flow of commissions, and it would, for example, provide insight into the number of projects he was working on at the same time.
The projects realized by the Cuypers family firm are dated from 1850 to 1958 and all described in the office archives. There are of course caesuracies to be pointed out over this period of a century. For example, the move of the architectural firm from Roermond to Amsterdam in 1866 was important, because the move also meant an expansion of the working area. Limburg, and Roermond in particular, remained of great importance to the firm because the art studio was always housed there and developed into a thriving business. Another caesura forms the year 1885, when J.Th.J. Cuypers joined his father at the firm, and the year 1900, when J.Th.J. Cuypers associated with J. Stuyt for a number of years. Also 1921, the year P.J.H. Cuypers died, can be considered a caesura.

Projects and advice
The cards of the first access to the Cuypers archive (the aforementioned card box) also contained information about the nature of the project: it could be new construction, a renovation, an extension or an advice. In theory, this last category of advice seemed an oddity. After all, it had previously been decided to make a distinction between office (and thus project) related activities and person-related activities. Giving advice seemed to be a person-related activity related to professional practice rather than an office-related activity. When Cuypers was asked to give advice on, say, a restoration, he was probably asked because of his expertise as an expert and was asked for his opinion. As such, the building on which his advice was sought cannot be considered a Cuypers project.
It was therefore initially assumed that the opinions belonged in the person-related archive rather than in the project-related section. However, Cuypers' practice threw a spanner in the works. There were several sides to his recommendations. Restoration and/or construction activities sometimes followed advice: as if one thing led to another. Moreover, Fons Asselbergs probably placed the advice between the design activities for a reason.
Further investigation into the nature of the advice did not make things any easier. It turned out that they were not just advice from Cuypers as a private architect. From 1874, Cuypers became a member of the College of State Advisors on Monuments of History and Art. This board was charged by the government with advising on alterations and restorations of Dutch monuments. When Cuypers was also appointed government architect of museum buildings in 1876, he became involved in various government remodeling and new construction projects, as well as government-subsidized restorations by third parties. At the end of his life, Cuypers cited the impressive number of 732 opinions he had issued for the national government.
However, the archival problem remained. By placing the advices among the projects, we would contribute to the myth-making surrounding Cuypers' enormous oeuvre. On the other hand, it is very forced to separate roles and functions, which were not so separated in the nineteenth century. Moreover, the list of Cuypers' diverse work does give a picture of, among other things, his indomitable work ethic, his undeniably great influence through his interference in everything, and his views on the ethical side of his profession.
Because of the argument of wanting to match Cuypers' conception of his task, his everyday practice and his time as much as possible, the choice was made to place his advisory work between the projects. The view that Cuypers did not regard his various functions and roles, from private architect to state advisor and state architect, as three separate areas in which he manifested himself professionally, but rather as natural parts of his performance as an architect in the broad sense of the word, is supported by the way he signed his letters, by the different nature of the letters in the copybooks, and by his actions on various issues.

Classification and Description
I General
As mentioned earlier, hardly any office records have survived. Those records that did survive are described in 'Documents concerning bureau organization'. In addition, the 'General' section contains the series of outgoing documents, as well as the financial documents and photo albums.
II Projects
In 1993, the card index was typed out by topography. This typed list formed the basis for the inventory on the Cuypers archive, which was in use until 2002. For the CUBA inventory, the sheets were again used, but now in chronological order. The Projects section is by far the most extensive and forms the backbone of the archive. Three periods can be distinguished:
1 Period 1850-1885 Period P.J.H. Cuypers alone.
2 Period 1885-1921 Period P.J.H. Cuypers and others.
3 Period 1921-1949 Period after P.J.H. Cuypers.
A project (file) description consists of the following parts:
Dating: the years for the project description indicate only the period marked by the dating of the oldest and youngest records. They often provide an indication of when construction of a project began, for example, or when the building was completed. In the absence of dates on the archival documents, an attempt was made to date the project through literature or through Asselbergs' map box. These years are then placed between square brackets [ ]. If the dating of a project could not be ascertained, the project is marked 'z.j.' (without year). Often an undated project can be periodized by the handwriting used. Then the project is placed at the end of the period.
The project description: this includes the typology of the project (church, residence, council house, etc.), the nature of the act (new construction, remodeling, expansion, etc.), the location of the project, possibly the architect(s) and client(s).
The explanation of the project: these will describe, if known, the different construction phases of the project, with the responsible architect and possibly with the specification number.
The nature of the documents: these indicate what kind of documents document the project, for example drawings, written documents, photographs, glass negatives or documentation.
The notes to the project file provide information for each document type. For the drawings, it describes what kind of drawings are involved (general drawings, specification drawings, detail and/or decoration drawings, etc.); by whom a drawing was signed or initialled; what stamps and/or numbers, texts and dating can be found on it and what scale was used. Written records and documentation are described and dated where possible. The images on the photographs and glass negatives are also described, as is the development process of the photograph and the name of the photographer, if known. Finally, occasional references are made to literature to be consulted and/or other archives where additional material on the project is located.

Material of others
The material of others is described with the project whenever possible. Often in this case the material can be considered retro-acta. It happened very frequently that Cuypers was involved in the extension of a building, for example, and drawings are therefore found from the designer of the building. When organizing such a project, the years on Cuypers' material are used as a starting point. After all, the drawings of the design can be considered precursors to Cuypers' design.
Of a number of drawings by others, the connection to Cuypers' projects is unclear. These drawings are described in the 'Material of other architects' section. It is not always clear why these drawings ended up in the Cuypers archive. Perhaps Cuypers used them as examples, references or sources of inspiration. Perhaps there were students who submitted material to Cuypers for review or advice.
However, it is known that material also ended up in the Cuypers archive unjustly. For example, in the past, the Cuypers archive, when it was still in the attic of the Rijksmuseum, got mixed up with the archive of submissions by various architects for the Jubilee Exhibition, held in 1923 on the occasion of Queen Wilhelmina's 25-year reign. Because the submission list for this exhibition was recovered, this archive could be reconstructed (see the TJUB collection) and the pieces were retrieved from the Cuypers archive. However, it is possible that other pieces whose provenance we can no longer trace may have remained in the Cuypers archive.

Finer, Finer, Finer......
A number of project files, drawings and/or photographs have been given the addition "fine" by the editors. Many presentation drawings with which Cuypers had to convince the client are very fine. This also applies to sketches, design drawings and the many decoration drawings. In addition, the extensive detailing in a number of working drawings is impressive.
The subjective character of the addition 'beautiful' is perhaps misplaced and certainly contradictory to our efforts to describe this archive as objectively as possible. Nevertheless, we felt it appropriate to add this panegyric. It is a tribute to the craftsmanship of Cuypers and can be seen as a helping hand to those users who make the archive known to a wider public at exhibitions and other presentations. Finally, in addition to being a collection of source material, the archive is also a museum collection of great aesthetic value. Already during earlier editing, Asselbergs assigned a veiled "fine" to drawings by stamping special drawings on the back and having the selected drawings photographed.

Conservation and restoration of drawings
During the inventory project, almost all drawings were seen and, if necessary, treated by paper conservator Peter Kipp. The overall condition of the drawings was reasonably good. For conservation purposes, all drawings were salvaged with a manageable size flat. That is, the rolled drawings were unrolled and the folded drawings, if possible, unfolded. It was then assessed whether the condition of the paper needed or could be improved. In assessing this, the (art) historical and administrative value of the drawing played a decisive role. For example, a highly detailed drawing of an ornament received more care than a working drawing drawn by hand.
Over time, the paper underwent aging, to which the different types of paper reacted to a greater or lesser extent. The most common problems were: crumbling of the paper (cause: aging), tears (cause: frequent use) and finally, the paper was sometimes very soiled (cause: poor storage conditions). The drawings were treated in different ways. The surface of the (locally) very soiled drawings was dry cleaned. Large tears, which could further damage the drawing in the future, were repaired. If further tearing could be prevented, complex cracks were fixed (secured). Where sharp creases increased the risk of future tearing, the creases were flattened. Drawings whose paper was very outdated and large drawings that could not be stored in common portfolios (the so-called giant sheets) were stored in a melinex cover. These melinex covers provide complete protection of the drawing. The paper is held in place in such a cover, eliminating the need for tear repair.