I realise this is a bit of a strange question, but what would bloodstains look like after ~500 years? Specifically, what would a text written on parchment using (human) blood as ink look like after 500 years?

Arterial, venous, and capillary blood all have different colours/characteristics, but is there any likelihood that when used as ink, they'd stay a vibrant red after half a millennium? I assume that blood-ink would go a kind of brownish colour after any length of time after it's dried? I want a manuscript with really crimson-red ink, but would my only options be something like red lead, vermillion, or brazilwood (your standard ingredients for medieval manuscript rubrics)? If blood on its own wouldn't work, is there any way it could be treated so that it stays really bright red?

I've read fantasy stories where there's some kind of creepy old magical text written in blood/made out of people, but to be honest it doesn't seem too far-fetched for reality... I'd just really like to know whether it's possible without magical intervention!

For context, I research late medieval European culture, so while I know a fair bit about manuscripts, I don't know much about blood... I've asked this as a 'hard science' question because I'd really like a citation that I can follow up, but that might take the form of "here's an example of something definitively written in blood, tested by science", or "here's a forensics paper that shows what blood looks like after different lengths of time", rather than the physics-heavy answers that this tag tends to get! I'm struggling to find an answer, because all my searches seem to come up with images of blood droplets in manuscripts, rather than actual literal blood used as ink.

EDIT: I've been alerted to the existence of this question, about what a deep pool of blood would look like after 500 years. While it's definitely interesting, it doesn't answer my question here, especially on the hard-science bit.

I also want to clarify that the parchment I'm talking about is either in a codex (standard book) or roll form, so it's not a single page that would be subject to massive wear-and-tear. Sure, 500 years takes its toll, but there are some amazing medieval manuscripts that survive really well, and they haven't degraded or decomposed.

  • $\begingroup$ I got a bit overexcited and closed my own question. Thank you for pointing out the existing question, but I think my scenario is different enough to be worth keeping open? Rather than it being blood left out in a pool in open air, I'm asking specifically about blood on parchment, and (as I'll add now) that parchment being bound into a book which survives to the present day. Not to say that the book will be pristine, but it'll be more likely to survive than a puddle of blood out in the open. $\endgroup$ Commented Nov 17, 2020 at 19:19
  • $\begingroup$ the blood would just as well decompose. Also: bloostains are brown to black, never scarlet red. $\endgroup$
    – Trish
    Commented Nov 17, 2020 at 19:24
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    $\begingroup$ Using blood as ink is possible, and has been done surprisingly often. To keep it fluid in the inkwell you need to add a little acidic anticoagulant, such as lemon juice. Use a quill or dip pen; it won't work in a fountain pen. The color of the writing becomes dark brown quickly, and it stays dark brown for a long time (at least several centuries), if protected (as in for example, on the pages a notebook). Sorry, not crimson. Here is an example of how it looks after more than three centuries. $\endgroup$
    – AlexP
    Commented Nov 17, 2020 at 20:00
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    $\begingroup$ You could use a standard deep red ink, mix it with some blood so the color is less familiar, and tell people you preserved it. That's technically "treated so it stays red" but it does rather feel like cheating. $\endgroup$
    – Cadence
    Commented Nov 17, 2020 at 23:02
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    $\begingroup$ @Cadence: There is no such thing as "standard deep red ink". As any ink lover will tell you, every ink brand is different. Here is Mountain Of Ink's page of reviews of red inks. You can surely find the red you want, or else you can just combine them. (And those are only modern inks; if you add traditional inks as used historically the gamut is even wider.) $\endgroup$
    – AlexP
    Commented Nov 18, 2020 at 1:13

1 Answer 1


Smudgy Brown.

Bloodstains can last myriads of years; but that deep lustrous red of fresh blood doesn't hold up at all well: they end up a kind of dull rusty brown.

We have plenty of bloodstained articles from Lincoln's deathbed, for example.

Move back a few more centuries, and we see in the Royal Armory Museum in Sweden the blood soaked shirt of Gustav Adolf.

Blood can indeed be used as ink. Here's a nineteenth century example of calligraphy written in blood in the late 19th or early 20th century.

The science is nothing more spectacular than the chemical changes haemoglobin undergoes when exposed to oxygen: haemoglobin --> oxyhaemoglobin (HbO2) --> methaemoglobin (MetHb) --> hemichrome (HC).

As you can see in the image, this change is pretty quick! About two days to go from bright red to dark brown. From professional experience, I can say that anything written in blood will be markedly changed after only 2 to 6 hours, having turned to a dark red.


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