Security paper
Encyclopedia
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
which incorporates features which can act to identify or authenticate a document as original or features which demonstrate tamper evidence when fraud
Fraud
In criminal law, a fraud is an intentional deception made for personal gain or to damage another individual; the related adjective is fraudulent. The specific legal definition varies by legal jurisdiction. Fraud is a crime, and also a civil law violation...
is attempted, e.g., to remove or alter print such as amounts or signatures on a cheque
Cheque
A cheque is a document/instrument See the negotiable cow—itself a fictional story—for discussions of cheques written on unusual surfaces. that orders a payment of money from a bank account...
. Examples of this kind of papers are those used for identification such as passports and certificates, such as birth certificates and different types of academic certificates.
History
An initial patent for the manufacturing process for security paper was granted to Robert E. Menzies and John E. Aitken in the early 20th century. According to the patent, the method by which security paper was produced involved using a soluble thiocyanateThiocyanate
Thiocyanate is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates...
(such as ammonium thiocyanate
Ammonium thiocyanate
Ammonium thiocyanate is an inorganic compound with the formula NH4SCN. It is the salt of the ammonium cation and the thiocyanate anion.-Uses:...
) and lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
, which could be used to create an insoluable salt, lead thiocyanate
Lead(II) thiocyanate
Lead thiocyanate is a chemical compound, more precisely a salt, with the chemical formula Pb2.Lead thiocyanate may be made by reacting lead acetate solved in water with either potassium thiocyanate or ammonium thiocyanate , thus causing precipitation of solid lead thiocyanate.Ion reaction:Lead...
. This compound would then bind to the paper pulp, adding weight and diminishing visibility of the inner contents of the envelope.