THE TECHNOLOGY of chemically watermarking paper was first patented in 1959 by Frans V. E. Vaurio for the Customark Corporation, a subsidiary of the Fox River Paper Corporation (now Company) in Appleton, Wisconsin. The Customark Corporation remains the sole patent holder for chemical watermarking of paper, though it licenses the use of the technology to other mills. Since the development of the procedure, it has been used exclusively for the watermarking of stationery letter stock and envelopes. In 1988, approximately 6.5 million sheets (13,000 reams) of paper were chemically watermarked by the Fox River Paper Company alone . Paper conservators in the near future should expect to routinely treat papers with chemical watermarks in archival collections and perhaps in modern art pieces.
“Watermarking” generally refers to a localized design, name, word, or date found in a sheet of paper. Strictly speaking, a watermark is a design. Smaller secondary names, words, and dates in the corners or opposite the main design are more accurately referred to as countermarks. However, the term “watermark” is used in this paper in the broader application, referring to the process of marking rather than to the content of the mark. The first watermarked Western paper dates from the 13th century. A cross and circle motif/design (Italy, 1282) is considered to be the first known Western example. Watermarks have not traditionally occurred in Eastern papers, although more contemporary examples exist. Watermarking originally might have been intended as an esthetic enhancement, a mark of quality, or a proprietary mark for the papermaker or the wealthy donor or client. Similar types of information, such as a particular brand of paper, manufacture from a specific mill, or depiction of a logo for a business or organization, are conveyed in watermarks today. Watermarks also relay historic information that can help date or geographically place a paper, thus validating a manuscript, document, or piece of art. The history and development of watermarks has been extensively researched. (See the bibliography for a brief listing of publications on the history, manufacture, and design of traditional watermarks.)
The crumbs from the erasure procedure were gathered and laid on the watermarked area. A thin polyester film was placed over the crumbs to reduce displacement possibilities. The papers were then stored on top of a blotter in a metal flat-file drawer away from light. After eight weeks, the papers were examined, and changes were recorded.
There isn't a consensus on what the earliest watermarks were for. They could have been to identify particular paper, or the manufacturer, or, in the service of kings, to convey a secret message or, more likely, to prove the provenience of the message. Watermarks eventually became used to mark different types of paper--or different batches. Remember that the 13th century was a time of Religious pilgrimage, and Romanesque churches of the times were full of carved symbols because few of the faithful could read. In that context, a symbol rather than a written message would be much more useful to the common worker shuffling paper around the known world.
And thus, after pressing and drying your sheet, you have made an artisinal paper with a wire watermark, the wire making the paper almost imperceptably thinner where it pressed into the wet pulp.
The high cost, inconvenience, and difficulty of producing intricate designs in conventionally manufactured wire or chiaroscuro watermarks were the impetus behind the invention of a simulated watermark in the commercial papermaking industry. The process of chemically watermarking paper allows for a greater diversity of applications at significantly lower cost. cites the costs and limits a0111s being approximately $300 for a dandy roll with a minimum order of 200,000 papers (400 reams) versus $20 for a chemical watermark pattern and a minimum order of 12,000 papers (24 reams).
With the Customark chemical watermark process, unmarked paper can be made in advance and stored. When an order is received, the watermark design is produced by stamping the pre-made papers and impregnating them with the patented compound under heat and pressure. While the manufacturer considers the resulting mark to be relatively inert . The marks in naturally aged samples are beginning to disappear into the surrounding paper structure. This phenomenon prompted interest in chemical watermarking and resulted in this investigation into some of the characteristics of modern chemical watermarks for the benefit of conservators.
Electro-type is a watermark in light where the hue is ‘strained’ so as to create a strong contrast with its surrounding surface. This allows it to be easily read but difficult to be forged.
CHEMICAL WATERMARKING is available under trade names such as Customark, Shadowmark, and Trustmark. Trustmark has a tagging material as a security feature that is mixed in the chemical watermark and changes color when exposed to chemical bleaches . Three chemically watermarked papers were supplied by the Fox River Paper Company for the purpose of experimentation. They were:
Watermark designs are created by sewing metal wires or soldering metal stencils onto a wire screen. In making paper by hand, the wire, known as a mold, is dipped into the wet pulp slurry is in a tub known as a vat. When the mold is removed from the vat, the excess water drains by gravity from the slurry. The fibers are distributed over the mold surface and deposited between the raised wires. In making paper by machine, the stock is run over or under the dandy roll, a wire cylinder to which the design is attached and which displaces the wet fibers in the area of design. Designs may also be impressed by localized pressure between metal or rubber rollers or dies. However the mark is produced, the result is an area in the paper that is less dense and thus more translucent when held in front of a light source. (See Further Reading for additional explanations of the variations and nuances of traditional watermarking.)
This watermark is produced by ‘flat’ technology machines during the making of paper, the contrasts in the hues are created by the different thicknesses of the fibres in the pulp mixture. As compared to a mould-made watermark, the hue contrasts are less rich and evident, however it still remains one of the most widespread and effective means against counterfeiting of value security paper.
Short-wave ultraviolet radiation (180–280 nm) is the easiest method of identification. Chemical watermarks appear dark and dull because components of the watermark absorb the short-wave ultraviolet radiation rather than fluorescing with these wavelengths of light . It is important to inspect both sides of a paper for a chemical watermark, as the marks are better seen on the side of impregnation.