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Thomas Gravell watermark collection

Identifier: MSS 0339

Scope and Content Note

The Thomas Gravell Watermark Collection includes 7.5 linear feet of material. The collection consists of over 7,000 slides of watermarks and the index cards which identify and date each one. Gravell collected images of watermarks on handmade paper made in both the United States and Europe, and his sources date from the 15th through the 19th centuries, although the bulk of the watermarks are from the 18th and early 19th centuries. Machine-made paper predominated after the 1830s, so Gravell’s collection extends little beyond this point in time. Also included are Gravell’s research notes, papers he wrote on the Dylux process and the research value of watermarks, and secondary source material dealing with papermaking and paper mills.

A watermark identified a papermaker, sometimes a broker, or the person for whom the paper was made. The watermark was formed by shaping thin wire into a design or letters or both and then sewing it into a paper mold. When a sheet of paper was made, the pulp was thinner where the wire had been, so the watermark was visible when the paper was held up to light. Not all paper was watermarked, but that of medium and high quality usually was.

Watermarks can help to identify who made a sheet of paper, as well as where and when it was made. While this can assist researchers in dating and authenticating documents, using watermarks for this purpose is not an exact science, even if the watermark itself contains a date. The paper may not have been used immediately after manufacture, and dates did not always indicate the year the paper was actually made. To compound the problem, highly regarded watermarks were often duplicated by other papermakers, and sometimes second-hand paper molds were sold and used by others with the watermark still attached.


  • Creation: circa 1970–1994


Language of Materials

Materials entirely in English.

Access Restrictions

The collection is open for research.

Terms Governing Use and Reproduction

Use of materials from this collection beyond the exceptions provided for in the Fair Use and Educational Use clauses of the U.S. Copyright Law may violate federal law. Permission to publish or reproduce is required from the copyright holder. Please contact Special Collections, University of Delaware Library,

Biographical Note

Thomas Gravell, an authority on watermarks, died at age 91 in September 2004. A resident of Wilmington, Delaware, Gravel retired from E.I. duPont de Nemours and Company in 1975 after 34 years of service. He became an expert on watermarks after devising an inexpensive means of reproducing watermarks and co-authoring two books on the subject. Gravell’s interest in watermarks began with the watermarks from his stamp collection and later expanded to include identifying and reproducing watermarks in paper that was made in the United States and Europe prior to 1830.

At the time Gravell began his research in 1970, there were two methods of reproducing watermarks. The first, tracing, was inexpensive yet failed to produce exact copies. The second, beta-radiography, was far more accurate, but was both time-consuming and expensive. Unhappy with these methods, Gravell learned that the Du Pont Company had just introduced Dylux 503, a photosensitive, instant image proof paper. Using this paper, he devised a new method for reproducing watermarks that proved to be inexpensive, accurate, and fast. Gravell placed the watermark on top of flourescent lamps and covered it with Dylux paper. Because the watermark was thinner than the rest of the paper, the flourescent light passed through the watermark with more intensity. The Dylux paper was then exposed to ultraviolet light which turned the watermark white and the unexposed area blue. The entire process could take as little as five minutes.

Using his new Dylux method to reproduce watermarks, Gravell’s second career was underway. He duplicated watermarks from manuscript collections in Delaware at the Henry Francis du Pont Winterthur Museum, the Eleutherian Mills Historical Library, the Historical Society of Delaware, and Special Collections at the University of Delaware Library. He also collected watermarks from the American Antiquarian Society, the Huntingdon County Historical Society, the Folger Shakespeare Library, and the Library of Congress.

In addition to identifying and reproducing watermarks, Gravell has also done research on papermaking, papermakers, and paper mills. His publications include: “Reproducing Watermarks for Study,” Proceedings of the American Antiquarian Society, Oct.,1972.; “A New Method of Reproducing Watermarks for Study,” Restaurator, 1975.; A Catalogue of American Watermarks, 1690–1835 (1979), with George Miller. New York:Garland Pub., 1979.; A Catalogue of Foreign Watermarks Found on Paper Used in America, 1700–1835 (1983), withGeorge Miller. New York : Garland Pub., 1983.

“The Wizard of Watermarks,” Du Pont Magazine (Jan./Feb. 1990) 84:1, pp. 4-6. Thomas Gravell and George Miller. A Catalogue of American Watermarks, 1690–1835. NewYork: Garland, 1979.


7.5 linear foot (17 boxes)


The Thomas Gravell watermark collection contains images of watermarks on handmade paper collected by twentieth century American watermark authority Thomas Gravell.


The collection has been divided into five series which reflect Gravell’s original use of the material in the collection. The first four series focus on the watermarks themselves, and consist primarily of Gravell’s slides of watermarks and the corresponding index cards which identify and date each watermark slide. Both the American and Foreign series include manuscripts, draft material, and camera-ready copy for the books that Gravell and his co-author George Miller subsequently published. In some cases Gravell’s research notes are included as well.

Gravell organized his slides in two different ways, either by the country where the paper was made or by the manuscript collection from which the watermark came. The watermarks that are grouped by country include United States (A), Holland (D), England (E), France (F), Germany (G), Ireland (T), Italy (I), and Spain (Sp). Those grouped by collection include Folger (Fol), Library of Congress (LC), and Thomas Jefferson (TJ) (from the Library of Congress). There are also some slides, labeled miscellaneous (misc), which Gravell was unable to identify. Each slide has one of the above abbreviations and a number in the bottom left hand corner. The slides are grouped by collection and then numerically within each collection. The corresponding identification cards are arranged either in the same numerical order or alphabetically. See the watermark list at the beginning of one of Gravell’s books for an illustration of his method of alphabetizing watermarks. The cards also have a collection abbreviation and number in the bottom left-hand corner so they can be matched with the corresponding slide.

Both the slides and the identification cards have an additional code, usually on the upper right, that indicates either the repository holding the watermarked sheet of paper, or the specific manuscript collection within that repository. These abbreviations are as follows: American Antiquarian Society (AAS), Eleutherian Mills Historical Society (H), Huntingdon County Historical Society (HHS), Historical Society of Delaware (HSD), Thomas Gravell’s personal collection (TLG), and Special Collections at the University of Delaware Library (UD). The Henry Francis du Pont Winterthur Museum collections include the Joseph Downs Manuscript Collection (W) and the Pennybaker Watermark Collection (WP). At the Library of Congress Gravell studied the Harrison Elliot Collection (HE-LC), the Peter Force Collection (PFC), the John Boyd Thatcher Collection (JBT, although many slides are labeled JCT), the Miscellaneous Manuscript Collection (MMC), and manuscripts from the Law Library (LL).

The final series of the collection, General Resources, has been subdivided into two categories. The first, articles by Gravell, deals primarily with reproducing watermarks, and with their value to researchers. Gravell compiled a bibliography on many aspects of paper and papermaking which is also included here. The second grouping under General Resources, Secondary Source Material, includes issues of The Papermaker, an article about Gravell that appeared in the Du Pont Magazine, and unpublished manuscripts on the history of the Curtis Paper Company (in Newark, Delaware) and the paper mills of New England.

Throughout the finding aid, it is important to note the changing box numbers to determine housing location for the various media in the collection (slides, cards, documents, etc.). Supplemental lists of slide inventories (by number) are available from the manuscripts librarian.


Multiple purchases, 1980 -1994.

Related Materials in other Repositories

For reference assistance with the digital watermark collectionPlease contact Prof. Daniel Mosser and Prof. Ernest Sullivan IIVirginia Tech, who have created a searchable electronic database on the Internet.

The Thomas L. Gravell Watermark Archive(

The database includes digital images of photographic reproductions of over 6,500 watermarks in paper made between 1400 and 1835 which form part of the Thomas Gravell Watermark Collection at the University of Delaware Library.

Shelving Summary

  1. Boxes 1-8: Shelved in SPEC MSS manuscript boxes
  2. Boxes 9, 11-13: Shelved in SPEC MSS shoeboxes
  3. Boxes 15-17: Shelved in SPEC MSS record center cartons


Processed by P. Tatnall, January–February 1997. Encoded by Natalie Baur, March 2010. Further prodcessing by Lauren Connolly, January 2016, and Tiffany Saulter, May 2016.

Finding aid for Thomas Gravell watermark collection
University of Delaware Library, Special Collections
2010 March 10
Language of description
Script of description
Language of description note

Repository Details

Part of the University of Delaware Library Special Collections Repository

181 South College Avenue
Newark DE 19717-5267 USA