Can you tell what that noise is? It’s the sound of money being printed. To be precise, it’s the sound
of euro banknotes being produced. It could be at any one
of the 11 printing locations in the euro area. Between 5 and 6 billion banknotes
are printed each year to satisfy demand and replace worn out banknotes. This is a highly secure area
and almost no-one is allowed to go in. Here, every can of ink, sheet of paper
and scrap of waste material is accounted for. The process starts with the production
of a very special kind of paper. Euro banknotes are printed
on paper made of pure cotton fibres. This gives the banknotes their special crispness and makes them resistant to wear and tear. At this stage, a watermark and a high-tech security thread
are embedded in the paper. A metallic foil is applied to the paper
using pressure and heat. At the end of the production process,
the paper is cut into sheets and securely transported
from the paper mills to the printing works. There are four stages to the printing process. The first stage is called offset printing. Here, a multi-coloured background
is printed simultaneously on both sides of the paper. This calls for extreme precision. Then comes the silkscreen printing when the emerald number
is applied to the front of the banknotes. The shiny ink contains special high-tech pigments which allow the number to change colour
from emerald green to deep blue when the banknote is tilted. The number also displays an effect of the light
that moves up and down. During the intaglio printing,
ink is applied to the paper under high pressure. This creates high-definition images and a relief structure that can be felt
on the left and right edges of the banknote. The numbering press
prints a serial number on the back of the notes. Each banknote is given
a unique combination of two letters and ten digits. The first letter in the serial number
identifies the printing works where the banknote was printed. For instance, these banknotes were printed in Italy. The printed sheets are thoroughly inspected,
by both machines and humans. Individual sheets are selected at random
during each production phase to ensure consistent quality
and identify any misprints. The sheets are counted
at each stage of the printing process. The printed sheets
are then moved on to the finishing process. With surgical precision, cutting machines
slice piles of 100 sheets into strips and then again into stacks of banknotes. The quality of the finished product
is then checked in an automated process. This ensures that all euro banknotes are identical regardless of where they have been produced. The notes are checked and counted once more
before being wrapped in self-sealing plastic film and neatly stacked in cardboard containers
slightly bigger than a shoe box. Each box is made to fit 10,000 banknotes. The freshly printed euro banknotes are
either stored in high security vaults or shipped via road, sea or air across the world ready to enter circulation. To find out more about euro banknotes, visit
www.euro.ecb.europa.eu.