Paper dating is not simple. Forensic Document Examiners (FDEs) have to delve in and check the minor details of questioned documents. And one of the minor details that are worth studying is watermarks.
Studying and examining watermarks can reveal important clues about their manufacturers, which can eventually lead to the age of the document.
And, that’s the aim of this forensic post. You will learn how watermarks assist in determining the age of paper.
How Watermarks Aid Paper Dating?
The approximate age of the paper is accomplished by comparing the QD samples with the known samples produced before and after the possible date of the document being questioned.
And the differences when comparing paper from known samples of different time periods, indicate that the questioned watermark paper is not the same.
But. But. But. This is not all.
Finding similarities alone cannot definitively identify a paper manufacturer.
There is more in it. As it could be a case of watermark forgery.
So, to give more certainty to your finding, other examinations such as checking physical characteristics, fiber analysis, chemical, and instrumental analysis, are needed to perform before coming to any conclusions.
Apart from this, there are commonly four ways to come up with the age of paper using watermarks. These are using:
- Change in Physical Entities
- Coded Watermarks
- Non-Coded Watermarks
- Instrumental Analysis
1. Change in Physical Entities
Using physical parameters of the watermark, the age of paper can be determined only when
- changes occur for the first time on a specific date/time, and
- prior to which those distinctive changes did not exist or were not made.
Following are some of the parameters by which an FDE can determine the age of paper by analyzing watermarks.
A. Change in Watermarks
- New logo/design because of rebranding, acquisition of the business by other businesses, etc.
- A part of the logo is changed
- Additional of embellishments
B. Fonts and Text Arrangements
- Addition of text as statement or tagline
- Change in text arrangement
- Space management between letters and words.
- Using different fonts
- Change in letter case: small or capitalized letter
C. Size and Dimension
- Size: relative increment or decrement of size should be brought into %age.
- Aspect ratio: whether the aspect ratio has changed or not.
- Dimensions: long, short, and diagonal dimensions should be compared to standard QD dimensions.
D. Relative Position and Arrangements
- Alignment of watermark with paper
- Change in position
- Change in rotation: Watermarks are sometimes printed in both directions to make them readable when holding the paper from any side.
2. Paper Dating Using Coded Watermarks
Coded watermarks have a characteristic marking usually as arbitrary marks, letter casing, the styling of fonts. These marks are usually aligned around the basic elements of logos or trademarks.
They are deliberately added by papermakers in order to define the date (usually the year) of the production of those papers. Moreover, they frequently keep changing over a period of time.
This makes coded marks more beneficial to FDEs in determining the date the paper was manufactured by a specific manufacturer.
Quick Fact: Practicing coding systems were first seen in the 1920s by paper manufacturers.
How Paper Manufacturers Coded Their Watermark?
1. Traditional Means: Using tie marks is common. “Tie mark” is a shape of an arc and outlined lettering.
2. Modern Means of Coding Paper Watermark: Variations in trademarks and logos are made using:
- Floating Marks: They are simple arbitrary marks using symbols such as o, x, dash (-), underscore (_), or a comma (,). Year after year or over a specific time period, these symbols are relocated to a specific element of the main logo.
- More than one arbitrary mark has been used that changes with time. Example; ox.
- A most common way of coding paper watermarks is by using underline dashes under letters.
3. Date Coded Watermarks: Watermarks with an undersigned date (mainly year).
- Very rare but often in security documents and banknotes.
- Very definitive means of age estimation of paper.
- Their occurrence is less than 10% (non-bank notes).
Limitation of Coded Watermarks in Age Estimation
- It requires additional maintenance than printing a normal watermarks.
- Very few in practice (mainly because of the above reason).
- Some manufacturers only practice for a short period of time.
- The coding of watermarks usually is a trade secret, which means that most of the coding elements are only known to manufacturers and their distributors.
3. Paper Dating in Non-Coded Watermarks
It is hard.
The first reason, more than 90% of watermarked papers are not coded. The second reason is that there is no clear indication in their logo itself when they were manufactured.
So, how to determine the age of paper of non-coded watermarks?
Firstly, studying design changes and from when they start manufacturing. The majority of paper manufacturers keep track of these changes.
Secondly, by studying the wear marks. Wear is common in dandy rolls.
Obtaining a known dated sample with wear from manufacturers can help FDEs to determine the absolute age of paper. Examiners can also collect samples of wear from dandy rolls manufacturers.
As it is clear from now, in analyzing non-coded watermarks, the examiner has to completely depend on the accuracy of logs and reports of paper manufacturers.
Without their accurate watermark logs, it is fairly difficult to line down the age of paper.
Role of Dandy Roll Manufactures in Paper Dating
Let’s assume the paper manufactured doesn’t maintain the record or somehow get destroyed. Firstly, it makes them highly suspicious.
But now as a forensic document examiner, what can you do?
You can approach Dandy Roll manufacturers. They are likely to have accurate records because:
- They prepare rolls for multiple companies
- Even for the government
So, they must maintain reports about the wear and newly issued dandy rolls.
Moreover, there are only a handful of Dandy rolls manufacturers in America. So, examiners don’t have to do a die-hard job in finding them.
Information that FDE can get from Dandy roll manufacturers:
- When the new design is implemented
- Purchasing and delivering (sometimes installing dates)
- Wear marks if revert back for repair
- Minute details in the design
Limitations: Still, the dandy rolls manufacturing report cannot state the exact date of production of the questioned documents, because:
- in a single day, thousands of paper reams can be produced.
- Plus, paper manufacturers usually buy a dandy roll in bulk (more than one).
4. Paper Dating Using Chemical Watermarks
It is very unlikely that paper manufacturers use chemical watermarking. Because it costs them extra money than the regular watermarking techniques such as a dandy roll.
They are, however, common for special orders where no bulk production is required. That’s why chemical watermarks are often used by small paper manufacturers.
The first step is to determine whether it is a chemical watermark or not.
The second step is the elemental analysis of the paper (check article: Analysis and determination of watermarks). And the third step is comparing them with known dated paper samples.
This doesn’t promise any certainty that it will lead to age estimation of paper. But, if the composition of chemical watermarks has changed and new additives have been added then using the company log report, the approximate age of the questioned document can be determined.
Limitation of Dating Using Watermarks
- Companies don’t change their watermark design frequently unless they use coded watermarks.
- More than 90% of cases used non-coded watermarks.
- Watermarks can help in the estimation of the age of paper but it can’t estimate when it was actually used. For that, dating from ink will need to be performed.
- Simple text watermark designs can be easily forged using typewriter typefaces or stamps. (Check the article: How are watermarks forged?)
- Modern enhancement makes replicating the design and printing chemical watermarks easy such as relief print using 3D printers.
- Need to identify manufacturer from standard known date samples. If they don’t have a sample or record, it becomes nearly impossible to age down that paper.
- Highly relies on paper manufacturers for standard paper samples. If they are the ones who forged watermarks, this misleads the investigation.
- Papermarkes start making watermarks with new designs and at the same time producing older ones too, or revert back to the earlier designs.
Which is the most distinctive way to determine age using paper watermarks?
Coded watermarks inducing traditional (tie marks), modern (dashes, commas, underscore, etc, added to a specific part of the logo), and dated (year of manufacturing) are the most distinctive way to determine the age using paper watermarks.
- Can a Watermark on Paper be Forged? Prevention and Detection
- Watermarks on Questioned Documents: Types and Significance
- Forensic Watermark Examination of Paper: Destructive And Non Destructive Analysis
- 14 Myths of Fingerprints And Questioned Documents: A Forensic Study
- Watermarks in paper: in Holland, England, France etc. [source]
- Scientific examination of questioned documents [book]
- Observations on paper as evidence [book]
- Paper and Watermarks as Bibliographical Evidence [book]
- A scientific method for forensic examination of paper [link]
FR Author Group at ForensicReader is a team of Forensic experts and scholars having B.Sc, M.Sc, or Doctorate( Ph.D.) degrees in Forensic Science. We published on topics on fingerprints, questioned documents, forensic medicine, toxicology, physical evidence, and related case studies. Know More.