Watermark paper were first introduced in Fabriano, Italy, in 1282.
Watermark paper were produced by impressing a water-coated metal stamp or “Dandy Roll” into the paper pulp during the manufacturing process and done by hand on a sheet by sheet basis
In 1826 John Marshall revolutionised the watermark process and made it easier for producers to watermark their paper, whilst new technologies have evolved over the years to further prevent tampering, counterfeiting, or otherwise duplicating sensitive and valuable documents.
As materials technology has developed, likewise the ability copy and fraudulently alter documents has unfortunately gained momentum as well. It has therefore been essential for security printers to keep (at least) one step ahead of both the opportunist and professional counterfeiter.
The base of many secure documents is the material on which they are produced and the controls surrounding its availability.
Most security papers incorporate features that can act to identify or authenticate a document as original, e.g. watermarks or invisible fibres in paper, or features that demonstrate tamper evidence when fraud is attempted, for example to remove or alter print such as amounts or signatures on a Bank cheque.
By far the most secure papers are those used in Banknotes, and whilst many of these are being replaced with the new polymer technology it is expected to be many years before all paper Banknotes move over to this.
What makes Banknote paper so secure is the content of the paper fibres which is mainly a cotton fibre (80-99%) originally sourced from common white linen rag. Technically it is not a paper but a cloth with the look and feel of paper.
Banknote paper is also made by a Cylinder Mould process which enables very distinct watermarks to be created and accurately positioned for placement within a Banknote design. The Cylinder Mould process also facilitates the inclusion of “woven” metallic and holographic threads, so familiar in today’s notes.
By its very nature this type of paper is expensive to manufacture and is therefore mainly limited to the currency market.
A more cost effective alternative to the Cylinder Mould process and by far the most widely used commercially is the Fourdriniér process, whereby the paper pulp is pressed between engraved rollers which impart a watermark pattern into the paper. This process utilises paper pulp which is commercially more cost effective than Banknote paper and opens up the use of watermark paper to everyday documents such as certificates, tickets, cheques and many other items of value.
Additional features which can be incorporated into the paper include:
- Embedded threads which are only visible when held up to the light
- Invisible Ultra Violet fibres – these are usually between 3mm and 10mm long and are sometimes incorporated as daylight visible coloured fibres in the paper surface.
- Planchettes – very small circular discs – sometimes micro engraved with images are another covert feature used in some papers.
- Tamper evident chemicals that react to solvents, acids and alkalis have been used in cheque paper for many years and still have a place today in many secure documents
Most Security Papers are “UV (Ultra Violet) Dull”, often termed as OBA Free, and do not glow under UV light as normal commercial papers do.
OBA stands for Optical Brightening Agents which are bleaches and other means of making the paper appear whiter. This is the reason most watermark papers are off-white in colour and is essential if invisible UV fibres or UV printing is to show up clearly on the paper surface.
As well as preventing the counterfeiting of documents, security papers also help detect fraud whereby attempts are made to alter the data entered onto a document, whether it be changes to the value of a Bank Cheque or to the examination grades or candidate’s names on Certificates, there are numerous areas where this is essential to a documents integrity.
Removal of laser printed data has become a greater threat as more and more organisations print their variable data in-house on desktop printers.
The incorporation of laser adhesion surfaces and special varnishes greatly diminishes the ability of toner removal and many security papers specify this as standard.
There are also special taggants incorporating a chemical “DNA” that can only be decoded by special means and act as a unique identifier for that material.
These can be electronically read to give and instant remote verification, particularly useful in the packaging and mass transit industry.
Since the introduction of digital copying and printing it has never been more important to use secure materials such as watermarked papers to give tangible and tactile credibility to valuable and sensitive documents.