When conversing about inks most people
think of colour, but this is of less importance to a printer than the sort that
is employed. The different options are discussed this month.
From 1840 onwards, ink has been an
important consideration. The red Maltese Cross postal markings applied to the
Penny Black stamp had proved to be hard to see and easy to remove, resulting in
re-use and loss of revenue. The colour choice was consequently reversed
resulting in the Penny Red stamp with a black cancellation.
Printing inks comprise different substances
depending on the process that is to be employed. They can include oils,
chemicals, pigments and other compounds to ensure the correct viscosity for the
printing press, process, paper thickness or coatings being used. Intaglio inks
are very thick and therefore raised, whereas most other inks are thin and
Stamps started out as single colour, then
could be bi-coloured and slowly incorporated four or more inks when perfect
registration of the design became feasible. Today’s advanced printing presses
can incorporate 14 or more colours in one pass enabling truly multi-coloured
stamps to grace our albums.
These days, printing inks can be split
between those helping to secure the product and those that are purely there for
a decorative purpose. Security-type inks can be machine readable, such as graphite,
phosphor or fluors. Stamps can also incorporate a specially formulated ink such
as ultra violet which glows under special lighting or be optically variable, changing
its colour when tilted (Castles high
values, for example).
Decorative types can include aromatic inks (a ‘scratch-and-sniff’ synthetic
eucalyptus was used on the Nobel Prizes),
might incorporate scratch-off latex areas (Magic),
or may be sensitive to temperature change (Weather).
Other tactile materials can now be suspended in a varnish ink, such as the Rock
of Gibraltar particles used on one of their issues.
It seems that there are now no limitations
as to what inks can be used on a stamp.
(The above article was written in 2007 for Royal
Mail's corporate website within its Stamps
and Collectables section.)
Version: 1.1, 2012. All material Copyright ©
2000-Date Glenn H Morgan FRPSL.