I need an ink that stands out on an original document but won't reproduce when copied. I sign papers all day long and my signature should not be reproducible.


There was a light blue/teal that did not copy with older copy machines.
Now with the new copier technology I don't know of a good option.



HELP please.

I've found that Herbin Gris Nuage barely shows up on photocopies if the lines were broad on the original.

Neil

Get a photo "gel" in some color that matches the ink well. They are available in sheets to put over lights in many many colors. Put that over the document (or just the signature area) to photocopy.

--John

John

This is to stop others from copying it. I work for a local City and someone copied another's signature on a legal document.


Just trying to keep it from hapening again.

Thanks

In my opinion, it can't be done and you shouldn't try. A good scanner can probably pick up things you can't see yourself. Once you have used your signature somewhere, somebody else can scan it and reproduce it.

Of course that means you shouldn't necessarily trust the signatures on documents you receive from other people.

I wish I could suggest a solution.

With modern digital scanning/copying, I think you may be out of luck. The time when copiers didn't pick up blue ink is largely a thing of the past. This is one reason why it generally is a good practice to always sign in blue ink -- and a nice juicy fountain pen is perfect for that. That way the original signatures stand out from photocopies. Some very light inks, such as highlighter yellow, still don't copy in most machines (although sometimes the highlighted text appears darker than surrounding text when it's highlighted), but I doubt you want to use yellow highlighting ink to sign official documents.

This is why I don't use black ink. No mistaking my signature for a photocopy or vice versa.

I have two signatures -- one for 'public' documents that a lot of people might see, and one for 'private', ie. banking or legal documents. If the wrong signature turns up where it shouldn't, it's easy to show.

Also, it you have a firm rule of only signing documents with a fountain pen, it's very easy to prove forgery.

Well, someone who wants to copy it would just use a scanner or fancier copier. Try using a "signature ink" that not only has a distinctive color (barely if it needs to be "black") but has a blend of White Whale to make it UV reactive and have a unique spectrum.

I echo others saying that technology will make it impossible to not have it copyable. I sometimes feel the back of the paper to see if the person really made the signature or it is a copy. A copy is going to be completely smooth.

But adding or using only a UV active ink would make sure just like they test dollar bills.

Kurt

I only use fountain pens and in 'different' colors. One signature is in Supershow green or Kelly Green. On letters I use, depending on the pen, either FPN Tulipe Noire, another purple, burgundy, or one of the R & K colors. Anything to stand out from regular ball point ink.

I never thought of adding white whale or a UV dye to my ink. (goes off wondering if white whale will mix with Diamine or R&K inks......)

The writeup of White Whale says it is meant for that. If you mix a few different inks -- a dash of this and a dash of that -- you will get a distinct spectrum unique to that batch. Keep a test slip signed with the date when you refill, and you can use that as the exemplar to show what a signature made i a particular date range should be like under spectroanalysis.

--John

Inks that often show through the other side of non-excellent paper (especially the lower-priced papers for laser printers and dry-toner photocopiers) might help prove the authenticity of a signature.

From my experience:
Namiki/Pilot Black (the brands' blue and blue-black don't make this list) (a little water-resistant)
Noodler's Luxury Blue (waterproof)
Noodler's "Swishmix" inks (from Swisher Pens) (mostly waterproof)
Swisher Pens's own store-brand inks (not water-resistant)
PR American Blue (not water-resistant)
Levenger Cobalt Blue and Fireball (not water-resistant)

I've heard that the PR quick-drying inks belong on this list too.

I often use a highlighter pencil if I need to write something that isn't meant to show in a photocopy. It's probably too light to sign documents with, but what about Noodler's highlighter inks? Has anyone tried?

If I can see it, I can copy it. Perhaps not using a B&W photocopier, but by taking it to a photo scanner or color copier. The limiting factor is the printer gamut.

So, using a color that is out-of-gamut for CMYK would be a good idea, since it could not reproduce the color. I don't know if you could tell by looking by eye, though. But it would mean that another scanner can tell the difference rather than requiring a more detailed spectrum.

--John

I agree that if you can see it you can copy it. And so we descend into geek speak...

If you write with it I can scan it. Photoshop is a wonderful tool and I'm going to look at the signature in various channels (RGB, CMYK or LAB for instance) trying to find one that mimics the brightness (darks & lights) of the signature. Then I'll sample the ink to find the base color and use that with the channel to recreate the variation in the color within the stroke. Then I print it to a wide gamut printer (something like the Canon pixma 9000's CcMmYKRG).

Now an 8x loupe and about 10 seconds is all you need to prove that it isn't your signature but a machine printout. Besides me how many people walk around day to day with an 8X loupe in their briefcase or bag? You could try a UV ink, or UV enhanced ink, but you run into the same problem with folks not running around with UV lights to watch your ink glow.

Simply put there is no easy way to guarantee that your signature won't be copied. You can do a decent job with an really inexpensive scanner and that printer you got for free when you purchased your computer. To do a good job will run about $1200 including photoshop. To do a great job will run about $4-5000 including color adjustment hardware and a high end wide gamut printer.

If someone wants to screw around with you, and is willing to invest the time and money, you really have to work hard to stop them.

How wide is it?
Ah, here.

So you can still use a visible green, blue, etc. that is way outside even the Adobe RGB gamut.

So far I've not scanned anything that was outside of Adobe RGB (except for the paper base being brightness-enhanced), but that gives me a reason to look.

--John

Who checks at all? Nobody will compare it one bit unless it is challenged, or for something very important.

I suppose the guy granting entrance to the safety deposit box room would be so prepared, as well as having the original card to compare with!



That's what witnesses and notary books are for. The signature it itself certified, not just an artifact in isolation.

It seems to me that a non-black bulletproof color is the best defense you're going to have. Even if somebody can accurately reproduce the color of Legal Lapis on a printer, you can always send it off to the lab for torture testing with a copy of your signature on the same paper with the real ink. I am guessing inkjet and even color laser isn't going to hold up like LL would.

I've been in a situation where something like this happened to another person in my last company.

I ended up doing my own dilution of Pelikan Turquoise. It partially disappears with standard photocopier settings. With a dark setting, it looks grey, and on a light setting it disappears entirely. This can be very useful.

Regards

Richard.