Would it be possible to use spider silk for armour, instead of metal?

I am not worried about how to obtain the silk. I know that spiders are not domesticable and that they are too aggressive to each others so that they cannot be lumped together like bees. (I can handwave all that; my spiders are just of a different species, unknown to us.)

But would it offer similar protection against pre-gun powder weapons? Would it be able to resist the thrust of a spear or an arrow, or the cut of a sword or knife (all made of common materials such as steel)? And how should it be used, lax, as a kind of shirt like chain mail, or would it be better to use it tense, as in shields? Would there be a particularly good way to weave the material for either use? And would it be transparent enough for use as a visor?

Thanks for the input so far.

A few things to notice:

  • these people's technology, spiderculture aside, is roughly Earth's 14th century, so no Kevlar or other things demanding sophisticated chemistry. They can stretch the silk in order to reduce its extensibility, and it seems a good idea;
  • they have no magic - they just happen to know a peculiar species of spider that can be domesticated (I don't need to explain why they are domesticable, they just are: Arachnia mirabilis, if you so wish);
  • the issue is important because it should have given them military superiority against their enemies: better or similarly armoured infantry and cavalry with much greater ability to maneuver, thanks to reduction in weight, and armored sailors who can survive a shipwreck or a fall into the sea;
  • my biggest concern is, if a soldier using such armour is hit by an arrow, would the arrow be stopped, or would it penetrate skin and flesh, carrying the silk together with it?

Edit to explain why I don't think this is a duplicate:

That question is about mixing spider silk, keratin, and bone, to make armour. It supposes high technology, and its emphasis is on how to produce the armour material. My question is about spider silk, in a middle age setting, and the emphasis is on how to use the armour, and what it would be able to resist.

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    $\begingroup$ Related, possible duplicate: worldbuilding.stackexchange.com/questions/20572/… $\endgroup$ Commented Jun 28, 2016 at 14:44
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    $\begingroup$ See also some of the answers to Could a creature evolve a biological “bulletproof vest”? $\endgroup$
    – user
    Commented Jun 28, 2016 at 14:55
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    $\begingroup$ There are several factors that might make it somewhat more realistic in your story's setting. The spiders are different than modern Earth species, their webbing may be different. The characters in your story may be better at weaving it or know a special way of weaving it. Maybe its treated somehow. Use your imagination! :D $\endgroup$ Commented Jun 28, 2016 at 21:23
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    $\begingroup$ Actually on one bridge across Vltava in Prague, huge spider colonies grow and they are not aggressive to each other at all. They chill together below the lamps and they are literally everywhere. $\endgroup$ Commented Jun 29, 2016 at 8:39
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    $\begingroup$ It might be interesting to note that in a literary example, spider-silk armour is used to great effect by many of the characters in Wildbow's Worm, owing to the main character's ability to telepathically control and therefore effectively domesticate spiders (amongst other things) and mass-produce silk. She starts with black widows as they're easier to source but uses Darwin's Bark spiders for their stronger silk later in the story when she has more resources. $\endgroup$
    – Carcer
    Commented Jun 29, 2016 at 15:07

8 Answers 8


Cloth armor - specifically, linen armor - was a thing, historically. It was used, tested, and could be quite effective. it was lighter and, reportedly, more comfortable and/or maneuverable than other armors, for the tradeoff of being also not quite as effective. Silk was more expensive, so there don't seem to be as much evidence for cloth armor made of silk - but on a cloth-for-cloth basis, there doesn't seem to be any reason the same kinds of techniques shouldn't work, if you have enough of the silk to make it cost-effective.

A Greek style armor called linothorax was reconstructed through using a lamination technique to transform linen cloth into stiff plates - essentially using multiple layers brushed with glue. This reconstruction was tested against arrows, and a thickness of 12mm supposedly would have been enough against any arrow the wearer was likely to encounter for about a 400 year period (see link for original tests).

Quilted Gambesons or Padded Jacks were sometimes used under other armor, but also sometimes used as a standalone. they were made from many layers, perhaps as many as thirty, of cloth quilted together - Linen was a popular choice as it was available, lightweight, and fairly effective (though some incorporated cotton, wool, or leather for extra effect). Testing of a reconstruction showed that such all-linen gambesons were an imperfect, but effective armor - the armor blunted some shots and reduced others to what would be lesser injuries from many of the arrows (though not all, depending on the arrowheads, see link for original tests), and proved somewhat effective even against spear or sword.

As for silk, I've vaguely heard of quilted silk armor being used (like the gambeson, up to thirty layers quilted together) among the Japanese and Koreans historically - and even in modern times, since this kind of armor may be bullet resistant, depending on caliber. However, I don't have nearly as good historical references, or testing information, about this kind of armor. Xplodotron's previous answer mentioned the use of a layer of silk and air pressure could deflect most (70%) of the arrows fired at it, which seems to indicate silk resists penetration pretty well as a single layer (compared to linen which I could not find used as a single layer for armor), and suggest that a layered silk version, like the linen armors, would be quite effective.

So your basic choices might be quilted silk, using many layers to resist the penetration of arrows, spears or swords; or else a laminated silk, where the layers are stiffened with glue to form a kind of plate mail. The first is going to be a lot more flexible, and probably easier to make, adjust, or work with, with the tradeoff of somewhat lower protection (arrows and the like might still penetrate, but much less than without the armor - and it does much less to protect against blunt force). The second is a lot more tricky to work with (and you'd need the glue, though a relatively low quality rabbit glue was well used) - and each piece of each armor must be separately laminated and fitted (it will resist tools as much as weapons), making it more labor-intensive but also a better protection.

Of course, since you plan for an abundance of spider-silk, maybe you could use both, either/or depending on the warrior and their role in fighting, or a hybrid with reinforced plates over vital areas, but quilted armor over other areas for more maneuverability.

I don't think you could make a visor out of it - you might get enough transparency to get away with a single sheer or gauzy layer, but you would get very little protection from it, and it would reduce visibility. At most you might deny your opponents an aiming point (faceless! aah!) if you used that single layer in conjunction with other silk armor, like a laminated silk helmet that does cover the rest of the face, but still allows openings like knights' helmets had for seeing through and such.

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    $\begingroup$ Thank you for the very detailed answer; it seems that the silk can be used in several different ways, allowing for various kinds of armour. Rabbit glue also seems an awesome substance! $\endgroup$ Commented Jun 29, 2016 at 12:16
  • $\begingroup$ @LuísHenrique - I'm glad you found it useful. I remembered the linen armor because it's so unexpected - then when this question popped up, I thought it would apply. And rabbit glue does seem cool - insta-armor, just add cloth. $\endgroup$
    – Megha
    Commented Jun 29, 2016 at 12:24
  • $\begingroup$ "each piece of each armor must be separately laminated and fitted" According to the Wikipedia article on linothorax, if the right glue is used the armor will actually soften and conform to the user's body for a time, so the fitting doesn't necessarily need to be exact. $\endgroup$
    – JAB
    Commented Sep 2, 2016 at 19:45
  • $\begingroup$ @JAB - Interesting, I guess the warmth and wear will gently shape them over time - though the armor must be fairly well fitting to begin with. I guess its kinda like leather sandals will conform just a bit over time, but have to fit to begin with. That sentence, though, meant to say that the laminated cloth was resistant enough to cutting that each separate piece had to be assembled from pre-cut cloth, and not made as large pieces, cut down to size and shaped afterwards. Probably easier to roughly shape them while gluing, though, even if the final shape relaxed into an exact fit later. $\endgroup$
    – Megha
    Commented Sep 2, 2016 at 20:01
  • $\begingroup$ For reference, the reason silk is so much more effective against arrows is due to the spin imparted by the fletching. The silk grips the arrowhead slightly and the twist causes it to grip tighter. This happens with regular cloth (try spinning a fork tightly in some kitchen roll and then pull it out), but perhaps silk being harder to cut/grippier than linen makes it more suitable. $\endgroup$ Commented Feb 23, 2019 at 9:54

Silk is a flexible material, so it simply could not replace metal in rigid armors like plate, nor in shields. You would have a soft, flexible armor more akin to chain mail, but much lighter.

However, silk is a tough material that resists cutting and tearing, and in fact in real life silk has indeed been used as armor, sometimes standalone but most often as an additional layer under something stiffer, such as leather or plate; the Mongols, for instance, often used silk as a backing for leather and metal scale and lamellar armors.

The advantages of silk as an armor are that it is lightweight, flexible, and breathable, while still providing reasonable protection against cuts and thrusts (it's obviously not going to do much against blunt force). Spider silk would only enhance all of these properties.

There's literally dozens of different ways to employ your silk as armor: A layer or two underneath plate armor can improve that armor's defense against piercing attacks such as spears and arrows; using it as a backing for scale or lamellar armors can make them more lightweight and more flexible, with little sacrificed in the way of protection; on its own, a few layers of spider silk could even provide proof against an assassin's bullet!

  • $\begingroup$ Do you have a link to support the civil war silk shirt point? I am curious about that one...and I must admit a bit skeptical. $\endgroup$
    – James
    Commented Jun 28, 2016 at 14:54
  • $\begingroup$ @James Actually looks like a few misremembered things that got scrambled in my brain, and then turn out to have been myths anyway, so I'm removing that claim from my answer. Sorry about that! :( $\endgroup$
    – Kromey
    Commented Jun 28, 2016 at 15:03
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    $\begingroup$ @James I do not know about the civil war but silk was used in bullet proof vest in the industrial age, see en.wikipedia.org/wiki/Bulletproof_vest#Industrial_era towards the end (or just search the page for silk) $\endgroup$
    – AstroDan
    Commented Jun 28, 2016 at 15:40
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    $\begingroup$ @DavidK I agree the headline is -- as is typical with "news" these days -- "uncareful", but the gist of it that the silk vest could have stopped a bullet fired from that gun into it is the salient bit to this topic. $\endgroup$
    – Kromey
    Commented Jun 28, 2016 at 19:05
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    $\begingroup$ Two things guys. One WWI would've happened anyways. Two (and I'm not 100% sure about this) the silk vests provide defense against low velocity bullets. That assassin was too close for the best to have saved the archdukes life. $\endgroup$ Commented Jun 29, 2016 at 2:56

Not only do you have to handwave the mass production of it, but you have to handwave how the armor is produced. But if you do handwave these things then yes, it may work well, although handwaving the production will be not so easy (think secret monk technologies of remaining former alien space race technologies).

Just from wiki: Spider silk

The original uploader was Vincentsarego at English Wikipedia - Transferred from en.wikipedia to Commons., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=40001987

$\tiny \text{By The original uploader was Vincentsarego at English Wikipedia - Transferred from en.wikipedia to Commons., CC BY-SA 3.0,}$ $\tiny \text{https://commons.wikimedia.org/w/index.php?curid=40001987}$

The overall strength is good enough.

  • Dragline silk's tensile strength is comparable to that of high-grade alloy steel (450 - 1970 MPa) and about half as strong as aramid filaments, such as Twaron or Kevlar (3000 MPa).

But what is good for spiders is not so good for armor. I mean the extensibity of silk. In tech there are known solutions for such things - there are pre-stretch building material.

That way if you stretch it and find a way to wind them together - you may have a product with different rigidity, from steel hard to rubber like stuff, as you choose.

And reasonable steel strength with less mass.

  • Consisting of mainly protein, silks are about a sixth of the density of steel (1.31 g/cm3).

The easiest way to prestretch it is to make cloth, stretch it and impregnate it with resin. You may loose some strength and other advantages, but it will better redistribute the pressure over the penetration area and will not bend into the chest at the place it gets hit.

But actually the bending ability can be used for better protection, in terms of stopping something.

Without resin, but with a magic-smart weave process, you may make armor as strong as steel, as hard as steel and with less weight.

So any Kevlar product and fiber glass, any carbon plastic - are good enough to show what may be done. Just the process of making these will be more tricky and the strength will be something between fiberglass and kevlar.

As Vakus Drake noticed there is Darwin's bark spider, which silk is at least twice stronger than usual in spiders community. Some properties are investigated in this paper, you may wish to read. And I find this quote from that paper hopeful for those who wish even more:

  • Thus we have available some 200.000+ unique silks that may cover an amazing breadth of material properties. To date, however, silks from only a few tens of species have been characterized, most chosen haphazardly as model organisms (Nephila) or simply from researchers' backyards.
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    $\begingroup$ Later in that article it says that the darwin bark spider has silk 10x as strong as kevlar which is way higher, so it's not clear what spider the prior stats are for, but due to selective breeding you should expect higher than average silk strength for this material. Not to mention it seems likely the OP would be assuming a spider whose silk is on the stronger side. $\endgroup$ Commented Jun 29, 2016 at 6:49
  • $\begingroup$ @VakusDrake nice note, I have read papers they referring to. Silk is 2x stronger then usual silk. These comparison are a bit misleading, because they comparing by (mass/volume)$\times$strength, it makes sense because silk is light weight material. I prefer volume comparison. Although did not understood how they come-up with 10x kevral. $\endgroup$
    – MolbOrg
    Commented Jun 29, 2016 at 18:30

If you allow more handwaving into your story...

Kevlar is a synthetic fiber. It is similar to spider silk in some ways, though Kevlar is more appropriate for armor not only due to availability, but also due to its mechanical properties. If you could get enough web to make a vest out of it, with technology similar to that used to make a Kevlar vest, you'd have a somewhat bullet-proof, somewhat slash-resistant (slightly better than nothing) but it probably wouldn't protect you against piercing nor crushing weapons on its own. Notice that Kevlar is somewhat like that too... It is made to protect you from bullets, but it is not rated for piece protection (i.e.: it is not stab-proof) for example.

TL;DR you could make a Kevlar-like vest with it, but it wouldn't be as good as Kevlar, and you have to do a lot of handwaving to make that feasible.

And it would not be transparent. Look at this vest made of spider silk, as seen in Wikipedia:

All in all, this could be an addition to protective clothing for people who work with dangerous materials or environments, but armed forces and police would probably fare better with other protective materials. And the people of your world would have to lack leather, metals, synthethic fibers or the technology to work with these to go for spider silk armor.

  • $\begingroup$ You are underestimating kevlar plenty of videos show how hard it is to pierce with a knife, i'm not sure "slightly resistant" really gives it credit it's certainly going to be better than linen armor. Plus darwin bark spiders can have silk ten times the strength of kevlar. $\endgroup$ Commented Jun 29, 2016 at 7:01
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    $\begingroup$ @VakusDrake the "strength" of a material does not tell how good it is to make armor. It means that for the same width, a string of that spider silk can bear more load (i.e.: hold a weight tied to it without breaking) than a string of Kevlar. But it does not tell us how it dissipates energy from impact, nor how the fiber holds against slashing nor piercing. $\endgroup$ Commented Jun 29, 2016 at 11:19

Billowing silk cloaks were used by horse-riding samurai to block most (not all) arrows. It's called a horo. See here: https://www.youtube.com/watch?v=8B_6BU7SYf8

Some horo had light framework (like a hoop-dress) to keep it billowed. To the extent that a shield is considered "armor," one could think of the horo as a silk shield you wear on your back.

I understand the OP uses the word "armour" in the question, but in a broader sense the horo is something that is worn which provides "protection" to samurai and messengers, allowing them to survive what would otherwise be fatal hits from attacking archers.

  • $\begingroup$ Yeah, the use of wind to make the silk more resistant to the arrow is a very nice idea, thank you! $\endgroup$ Commented Jun 28, 2016 at 21:26
  • $\begingroup$ Though interesting, it does not seem to be an answer to the question. $\endgroup$ Commented Jun 28, 2016 at 21:52
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    $\begingroup$ @Hohmannfan - I was just trying to show another use of silk that can "offer similar protection against pre-gun powder weapons." $\endgroup$
    – Xplodotron
    Commented Jun 28, 2016 at 22:48
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    $\begingroup$ That is not an armor. $\endgroup$
    – Vincent
    Commented Jun 29, 2016 at 0:22
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    $\begingroup$ I played Total War 2: Shogun and I saw that too. Nice to see it mentioned here. That could make spider silk have some armor use. If you elaborate your post more, I will upvote it (please see Rom Review's comment, right above mine). $\endgroup$ Commented Jun 29, 2016 at 14:37

Let me introduce you to the golden silk orb-weaver, this spiders silk is known for its tensile strength. It is indeed so strong that if it was as thick as a pencil, it could stop a jet! In 2012 a cape was even mad using this material and if its molecular compound can be determined, it will easily replace kevlar.

enter image description here

  • $\begingroup$ I know the picture was in Renans answer, but I couldn't find the image of the 2009 cape $\endgroup$
    – TrEs-2b
    Commented Jun 28, 2016 at 17:09

There is already a historic precedent: Genghis Khan had his soldiers wear silk armor beneath their normal protection. Anecdotally, Genghis Khan's soldiers took arrows that penetrated the traditional armor, and should have killed them, but were prevented from doing harm by the silk, lending to stories of the soldier's invincibility.


This is actually being attempted, although an regular spider's silk would not stop much there are actually ways of making it work, i must point out that at some point in history even paper was used to make armor and it was effective (100% sure about that just google) this would work by adding several layers of it making it a really good armor (same protection as chainmail) but would bot last a lot after a few blows blocked it would be wrecked. Nowadays, there is an on-going attempted to create an real life a bulletproof vest made from spiderweb as their tensile strength goes toe to toe with steal without being as heavy (100% sure about that just google), and it does sound to me that if there was a population who lived closely with similar spider could have picked up some sort of way to make the armor you spoke of.

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    $\begingroup$ Your question made me join this page just so that i could answer. Oh and the spider is not the golden silk orb-weaver. very different spider. $\endgroup$ Commented Jun 29, 2016 at 9:04
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    $\begingroup$ Hi Pedro, welcome to Worldbuilding and thanks for the interesting answer. If, instead of "100% sure about that just google", you could provide some references, that would greatly improve your answer. I encourage you to have a guided tour, or peruse the help center. And if you have questions, you might take them up to Worldbuilding Meta, or, once you get enough reputation, join us on Worldbuilding Chat. $\endgroup$ Commented Jun 29, 2016 at 9:12
  • $\begingroup$ @bilbo_pingouin i am at my coffee break, i know i should provide references but wifi here is controlled and checked every day, stack exchange is fine because we have to use stack overflow a lot but to be googling about spiders... boss wouldn't enjoy that $\endgroup$ Commented Jun 29, 2016 at 9:17
  • $\begingroup$ There's no rush, but it would really improve your answer... afterwork maybe :) $\endgroup$ Commented Jun 29, 2016 at 9:19
  • $\begingroup$ @bilbo_pingouin Spider is Darwin's bark spider, although as tested on cellar spiders (aka long legged spiders) it is thought that when spayed with carbon nanotubes and graphene flakes can increase the web strength. This are the bits that are coming to memory right now but i'll be sure to include some interesting articles later. $\endgroup$ Commented Jun 29, 2016 at 9:37

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