Voorn notes that the watermarks on large-sized papersare generally not represented in Dutch archives. Other paper historians such asHeawood and Churchi11 however did examine watermarks on printsand maps and thus can be more useful in studying watermarks in largeart papers.
In Islamic papers the chain lines are either irregularly spaced or, if regularly spaced, are arranged in groups of 2's (on the oldest papers until the beginning of the 13th century) or 3's (beginning in the 1200's and then dominating) or alternating groups of 2's and 3's (introduced around the 1380's in Syria and Palestine).
The symbol used for the Lydgate paper watermarks is a fairlycommon one, a shield or cup shape containing three connected fleur-de-lissymbols, with a series of floral shapes above and a stylized Gothic letter"T" below. The most obvious differences between Type 1 and Type 2 arefound in the lower fleur-de-lis and in the letter "T"; in the Type 1watermark the vertical leaf of the fleur-de-lis points somewhat to the rightwhile in Type two it points somewhat to the left; letter "T" isthicker in Type 2; and the flourishes on the end of the "T" crossstroke differ markedly between Type 1 and Type 2.
The Lydgate manuscript paper hastwo distinct watermarks, arbitrarily designated Type 1 and Type 2. (Thewatermarks in the images below have been digitally traced from backlitphotographs and enhanced for clarity.)
The medieval process of normally required the useof two or more moulds for each batch of paper. The moulds would start out moreor less identical, but would develop variations in the position of their variouselements over time. The watermarks on each mould would initially be as similaras the artisan could make them, but no two shapes formed from wire could beexactly the same, so even when new the watermarks on each mold would be somewhatdifferent. This difference can be used to determine the minimum number of mouldsthat were used to produce a given batch of paper; in the case of the Lydgatemanuscript that minimum number is two.
But watermarks on large art papers mayfrequently not be published at all because some paper historianssuch as Briquet and Voorn have focussed their studies on manuscriptsin archives.
Another mark shows the letter "S" placed to one side of a circle;another symmetrically placed letter has apparently fallen off themold:If a researcher is fortunate and matches a watermark with anidentical published mark, then the date and place of use of thecited paper sheet can be used to infer a time period for the use ofthe paper mold which made both sheets.
Quite different seventeenth-century versions of the IHSwatermark occur on an Italian paper used for a Claude print (with acentral chain line crossing the mark) and on prints by Callot onFrench paper (with chain lines crossing the mark at left and right).
While another Claude print lacks awatermark, it clearly shows the same channeled effect and is thus ona closely related paper. Channeled paper is also found on someSchongauer prints.
American Paper and Pulp Association.
1965. The Dictionary of Paper, including pulp, paperboard, paper properties and related papermaking terms. 3rd ed. New York.
By comparing the paper andwatermarks that we find, we can learn to recognize the papers thatreoccur and those that are uncommon or from a posthumous reprinting.
The author argues for caution in dating incunabula solely bywatermark evidence and reminds the reader that the date of papermanufacture only gives at best the earliest possible date of use,but not necessarily the actual date of use.
The basis of the study of watermarks is that at a given period oftime a specific paper mill would have on hand a limited number ofpapermaking molds, and these molds had a finite useful life.
The author attempts correlating the dates of unwatermarked papersfrom the earliest era of European papermaking with chain lineintervals and laid line frequencies.
He points out that currentpaper research sees the basis of paper history to lie not in datingthe watermark per se, but instead dating a sheet of paper producedby a specific mold.