On 24/01/2018 23:45, ss wrote:
On 24/01/2018 23:39, Graham. wrote:
I have 3 `copies` of a document.
1 is original (ball point) and 2 are copies (laser printer)
They all look similar, so does anyone know of a way to differentiate the
`wet signature` from the copies.
I have tried a UV light but doesnt show a difference.
Without causing any destruction as they are legal documents.
Take them out in bright sunshine tomorrow (yeah right) and compare
them carefully for any difference of emissivity or colour hue.
After that, if you can't detect a difference, I doubt any court will
either.
I`ll give that a try weather permitting :-)
What happened was the 2 copies and the original were all mistakenly
stamped as authenticated copies despite 1 being an original when they
should only have stamped the 2 copies.
One way that might well work is look at the reverse side of each piece
of paper lit from the side at an oblique angle. The one which was
physically signed with a biro should have a slight change in paper
height where the nib has squashed the paper fibres. Unless like in
classic spy movies they used a sheet of glass to lean on.
Failing that and only slightly destructive a solvent like meths or white
spirit will dissolve biro ink but not affect the laser copies. A sort of
variant on the old spirit duplicator printing method.
https://en.wikipedia.org/wiki/Spirit_duplicator
My suggestion for a way to find the original is therefore wet a small
area of blank white paper with meths - let it soak in until there is no
surface wetness. Then press the solvent infused paper against each
signature. When you get the real one it will pick up some ink.
Try not to smudge it you need to put the paper down and lift it up again
without dragging sideways.
You may want to practice carefully on a sacrificial test piece first.
If you can guess correctly which are the copies by other means you can
confirm it by using this solvent test. Laser toner is thermoplastic.
Do not under any circumstances apply solvent directly to the biro
signature or it may be seriously degraded.
--
Regards,
Martin Brown