# Is blue ink easier to copy/forge from a signature? **URL:** \ **Category:** Factual Questions\ **Created:** [December 19, 2023, 6:39pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832 "2023-12-19T18:39:50Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Love\_Rhombus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/love_rhombus/32/10694_2.png) [@Love\_Rhombus](https://boards.straightdope.com/u/Love_Rhombus)\ **Post date:** [December 19, 2023, 6:39pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/1 "2023-12-19T18:39:50Z")
Actors and celebrities sometimes refuse to sign items with a blue pen because they’ve been warned that it’s easier to replicate than black. Is this true about the ink? > **[Claire Foy refuses to sign autograph with blue pen and fans reveal why](https://metro.co.uk/2023/12/18/claire-foy-refuses-sign-autograph-blue-pen-fans-reveal-19989692/)** > > What did we just witness? ---
**Author:** ![peedin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peedin/32/14095_2.png) [@peedin](https://boards.straightdope.com/u/peedin)\ **Post date:** [December 19, 2023, 6:41pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/2 "2023-12-19T18:41:26Z")
My ex husband always signed business documents in blue ink so he could tell the original from a photocopy. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [December 19, 2023, 7:11pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/3 "2023-12-19T19:11:49Z")
No, and, to the extent it was ever true, it would now simply be superstition. Photocopiers do better or worse with different colors, especially an old copier, but that’s not usful for today’s forgers and especially for fake autographs. The trick for selling contemporary signed sports & celeb stuff has nothing to do with the appearance of the pen marks and everything to do with authentication confidence. I did have a bank teller …tell me only black ink could be used for a deposit slip or something mundane. Again, it’s not true but I wasn’t in the mood to argue at the time. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [December 19, 2023, 7:32pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/4 "2023-12-19T19:32:25Z")
My mother recently sent her passport for renewal and the postal clerk had her write over some blue text with a black ink pen. ---
**Author:** ![TheCuse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thecuse/32/2854_2.png) [@TheCuse](https://boards.straightdope.com/u/TheCuse)\ **Post date:** [December 19, 2023, 7:35pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/5 "2023-12-19T19:35:40Z")
I remember back in the 80s when I was in the Air Force we were instructed to fill in forms in black or dark blue ink. Was even an instruction on the form itself saying that. Of course times have changed since then. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 19, 2023, 7:41pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/6 "2023-12-19T19:41:01Z")
The blue ink is used because it does _not_ show up well in a photocopy: > **[Non-photo blue](https://en.wikipedia.org/wiki/Non-photo_blue)** > > Non-photo blue (or non-repro blue) is a common tool in the graphic design and print industry, being a particular shade of blue that cannot be detected by graphic arts camera film. This allows layout editors to write notes to the printer on the print flat (the image that is to be photographed and sent to print) which will not show in the final form. It also allows artists to lay down sketch lines without the need to erase after inking. > More recently, with digital scanning and image manipulation, ... ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [December 19, 2023, 7:41pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/7 "2023-12-19T19:41:06Z")
> [@peedin](#): > > My ex husband always signed business documents in blue ink so he could tell the original from a photocopy. Exactly. I have stacks of blue pens here because I picked that bit of wisdom up somewhere and, besides, it really is more immediately visible as most copies I get are still in black and white and not color copies. Plus I also like the look of blue ink over black. And make mine a medium point, like 1.0mm, not this fine point stuff which feels like I’m scratching the paper all the time. ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [December 20, 2023, 4:37am UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/8 "2023-12-20T04:37:53Z")
> [@Dewey\_Finn](#): > > My mother recently sent her passport for renewal and the postal clerk had her write over some blue text with a black ink pen I seem to recall that the passport application specifically states you must use black ink only. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [December 20, 2023, 5:29am UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/9 "2023-12-20T05:29:01Z")
I suspect that this is nothing to do with forgery and more an artefact from the days when copiers were not as good as today and blue (especially pale blue) would tend to become indistinct particularly if something was copied serially (a copy of a copy of a copy etc). ---
**Author:** ![Capn\_Carl](https://avatars.discourse-cdn.com/v4/letter/c/838e76/32.png) [@Capn\_Carl](https://boards.straightdope.com/u/Capn_Carl)\ **Post date:** [December 20, 2023, 6:05am UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/10 "2023-12-20T06:05:29Z")
Back when documents were recorded on microfilm, blue ink was avoided when possible because the black-and-white film used in microfilm cameras wasn’t very sensitive to blue ink. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [December 20, 2023, 7:46am UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/11 "2023-12-20T07:46:57Z")
Celebrities are often told to avoid pens but use Sharpie type markers for signing autographs because of the lower friction liquid ink. When you are the guest at a convention or a book signing, and will be signing autograph after autograph for hours, that can make a difference in how tired your arm gets. Non-repro blue was a thing, back when most graphics was done via film camera. But now it’s nearly all digital for cameras, scanners, copiers, etc. that doesn’t matter much any more. And even 30 years ago, when I worked in the banking industry, we had yellow plastic overlay sheets we could place over original documents while copying them; these would make the blue appear as black and show up clearly. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [December 20, 2023, 8:41pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/12 "2023-12-20T20:41:06Z")
That’s what I was always told as well. Blue ink used to photocopy as black, and even with a color printer, doesn’t look quite the same as the original. I would imagine in a security sense, you’re probably better off with something truly funky- some [weird fountain pen ink with metallic flecks in it](https://www.gouletpens.com/collections/jacques-herbin-ink/products/jacques-herbin-1670-emerald-chivor-50ml-bottled-ink), or something along those lines. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 21, 2023, 6:17pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/13 "2023-12-21T18:17:57Z")
Originally, black and white film was only sensitive to bluer light - red registered as black, the absence of white/light. Blue registered much lighter. Hence, early movies and photos the actresses appeared to be wearing very dark lipstick, because the red did not register. Urban legend has it actors would use very white makeup so that their faces did not appear dark in silent movies, before film tech got better. Also why B&W print paper can be handled in darkooms with a faint red light because it is specifically not red-sensitive to make this sort of work easier. (But modern film is panchromatic so cannot be exposed to any colour of light during handling in the darkroom). I suspect the original warnings were because ortho film at the time would not pick up blue, so any blue ink signatures and such would not be captured. I suspect this is why **TheCuse** was told to use black - microfilm/archive copies of documents would be unreadable. Anyone who remembers the early Xerox machines, the light tended to be a bright green, which would likely register lighter blue as white-ish on white paper, not black. When I was in college and helped layout the college paper, the guidelines on the layout sheets was a grid of faint turquiose blue - precisely because it did not register on ortho film making the master plates. (The non-repro blue **DPRK** \* mentions.) Perhaps this “don’t use blue” mantra has been repeated and misunderstood over the years. Today, most imaging is panchromatic, has no problem telling blue or red from white. Besides, most “blue” is pretty dark ink. I would think celebrities would _want_ their signatures to be harder to copy. ---
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [December 21, 2023, 6:19pm UTC](https://boards.straightdope.com/t/is-blue-ink-easier-to-copy-forge-from-a-signature/994832/14 "2023-12-21T18:19:10Z")
I had read that many celebrities use a totally different signature for public autographs than what they use for their bank forms, legal documents, etc., anyway, as a precaution.