Banknote novice needs help - manufacturing techniques.

Hello banknote lovers!

I am not much into banknotes, but I would like to know some basics about manufacturing techniques of banknotes. 

Could anyone please simply explain intaglio/letterpress/Screen printing/Lithography techniques? I am quite lost here.  😑

I understand overprinted, cut, perforated and offset as they are self explanatory a bit :D

Best regards,

Jarek

Intagio printing is the raised print on a banknote. It is high quality, expensive, and difficult to forge easily or cheaply. Intaglio printing is usually the final print run on a banknote. This printing is done from an engraved plate, where the design is cut out from the metal and the ink is applied from these cut areas.

A less expensive high quality printing typically on banknotes is offset printing, which prints the flat colour on banknotes, usually in one, two, or three runs, depending on the level of security and face value of the note:
https://www.fleur-de-coin.com/eurocoins/banknote-production
https://www.komori-currency.com/
https://www.jenningsprint.com.au/how-does-offset-printing-work/

Letterpress printing is an older printing process, often used to add the serial numbers. The process involves using a raised surface to apply the ink.

Screen printing is not used on banknotes. It uses a mesh to apply ink. The best resolution from this process is around 240 dots per inch (dpi).

Well said Hibernia.  Many of the older Czech and Slovak notes were intaglia…if you brush your finger over the design you will feel the ink.  If you go to the thread on the North Korean 5 Won video I did, it shows examples off the same note design, but one is intaglio while the other is not.

You can always feel the raised intaglio print on a banknote down to VF grade or so, except when the note has been pressed or washed which flattens it out.

By coincidence, I spent much of today in the Bank of Ireland in Dublin, in the old print house where the bank used to print its notes in past times. We looked at some of the intaglio printing plates, as well as offset printing plates used for post bills. The offset plates had the image of the notes raised several millimetres from the plate body, while the intaglio plates were the opposite, with deep engravings on steel plates. All works of art!