Original Paper Banknotes.

It depends on what type of paper the original note was made from. In the US that might be colored silk threads embedded in the paper. It could be a watermark, or a security thread. It could be the fineness and quality of the printing. It may be a counterfeit note with a known block/serial number that is the giveaway.

KK

The paper used for notes is a fine quality mixture of cotton and linen. The ingredients used for the paper are primarily ''RAGS'' which are first cleaned mechanically to remove dust and foreign matter, and then boiled in a large rotary boiler with lime under steam pressure for several hours. the lime removes impurities and colours. The rags are then transferred to a machine which reduces them to individual fibres. To the fibrous material is then added resin or glue,colouring matter, and fillers to produce a consistent product. This process was for Australian Pre-decimal banknotes...The first thing I do is put the note under UV light. It will show PVC stains, which cannot be seen under led light. Also detect if note has been cleaned. If the note lights up bright its been washed. if dull its OK. Never ceases to amaze me how some banknote sellers either don't know how to detect if a paper note has been doctored or are they just liars and cheats...

Banknote doctors cannot beat the UV light. They can still keep the paper crisp and firm by very slow drying in a cool place..

-I agree with "coaster" and to make matters worse, you have not backed up any of your claims to know exactly how pre-decimal Australian note paper was created? Where did you get your information from (what is your source)? Then, without any other proof, you accuse some "banknote sellers" as being "liars and cheats."

For Canadian notes, you can turn to our Charlton Guide which explains that for 1935 notes "The paper composition was 75% high grade flax and 25% cotton" on p201 of the 30th Edition (2018)

Although UV light helps- it is not your only way to detect whether a note has been processed. Holding a note up (at an angle) to light will usually be good enough to detect the note's imperfections. As note's increase in grade (towards Gem UNC) finding problems with the note becomes more challenging. KK and I gave perfect examples of how to detect problems in North American paper money. I have some 1939 and 1960 Australian notes and find the same principles apply.

ALSO-"WALK2DWATER'' I have plenty of proof regarding some ''Banknote Sellers'' who over grade there notes. But I wont list there names on this site.When you study and collect + purchase banknotes for a long time you get to know WHO'S WHO'in the ZOO...Unsuspecting newcomers purchase a note described as UNC only later to find out it's only A/UNC. They become so disheartened they stop collecting and this is BAD for the industry..