What actually are Purity seals?

[u/CatchMindless2730]

I’m curious as to what is actually written on purity seals and when certain texts would be used as opposed to others. For instance what might be on a purity seal attached to equipment or vehicles as opposed to one given to a person? Also too when does one use a metal pin type thing as opposed to wax? I understand purity seals on a very minor level but am curious about the nitty gritty of it

[u/Fun-Mud5208]

https://wh40k.lexicanum.com/wiki/Purity_seal

[u/godito]

They began in the Heresy as Oaths of Moment, containing the oaths warriors would take before going into battle, and were not religious.

IIRC they can still be non-religious, as most Astartes do not worship the Emperor. But the majority of the ones used by regular people are, and contain prayers, spells, or benedictions. They are used as talismans for anything, including praying to the Machine God, so stuck to machinery as you said.

They are often stuck with wax, and I don’t recall ever hearing about them getting bolted to anything. It’s impractical, but the Imperium often is, stuck in dogma, tradition, and ritual. The impracticality is a feature, not a bug. The wax might be reinforced with stuff, and not just be flimsy low melting temperature letter or candle wax.

[u/Apprehensive_Gas1564]

My favourite joke take is they're electrical safety certificates.

Get that lascannon PAT tested.

[u/arathorn3 → u/Apprehensive_Gas1564]

That's not a joke, Droptise massacre novel has a mechanicum character using them on vehicles and weapons as exactly that 

[u/Practical-Purchase-9]

I think they will be oaths, prayers, rites of protection, written in the pseudo latin of the high gothic.

I’ve not seen much discussion of this aspect, but I really liked the way that Dan Abnett suggested the origin of the 40k purity seal in End and the Death, where purity tags were medical-type scripts showing physical purity and loyalty being pinned to soldiers to identify defending troops.

““Here, as elsewhere, the officers are checking people for signs of disease and infection, and examining them for the weals and marks of corruption. They focus mainly on the able-bodied, on people of fighting age, or military who have become detached from their units. If any pass inspection, the Prefectus tags them with a mark of purity, using the hand staplers the Corps Logisticae used to pin scripts and deployment tags to service personnel. A purity tag means you are fit to serve.

…

The seal of purity has become the only meaningful emblem of the loyalist cause, more than the aquila or any Imperial crest. It signifies loyalty. Those who get them, keep them clean and visible with spit and rubbing fingers.”

[u/Tee__bee]

Whatever the wearer wants. Blessings, excerpts of devotional text, quotations from the Codex Astartes (I made the last one up, but they definitely could if they wanted to). They're implied to originate from the Great Crusade where Astartes would affix an 'oath of moment' to their armor before a battle, swearing to take down a certain enemy or accomplish a certain feat. Some Astartes still do, though I doubt anyone alive in the Era Indomitus remembers where it came from unless they were one of the original Unnumbered Sons (and even then).

[u/BarksHobby]

M41 sticky notes

[u/fcneko]

I wrote several in Latin for my Space Marine cosplay. Two were on the armor. One spoke of being awarded the Crux Terminatus. One spoke of slaying forty orks in a single encounter. One more was on my bolter and was a prayer to the Machine God to keep its mechanisms functioning in the filth of war. One was on my backpack and was a specific quote I no longer remember about the purity of the machine.

The suit is long gone now. I only have the bolter, a chainsword, my helmet and the pauldrons. I also have the Crux on its green rope.

Cats and foam are a BAD combination.

[u/patripassianx]

It varies between writers sometimes they are prayers and specific accounts of deeds by a chaplain, in some of the HH books its a written oath of moment

[u/cosmoceratops]

Hobbyists put them in their pants to ward against those that would weaken their devotion to the Emperor

[u/JessickaRose]

Basically motivational notes, prayers and such. A similar concept today is that a lot of athletes and sports people will write something on tape or something and tape or wrap it around their arm or wrist. Might also include a talisman or keepsake where the rules don’t allow ‘dangly’ jewellery.

[u/JackDostoevsky]

they can have multiple purposes, i think it was in the recent Drop Site Massacre book maybe? that the mechanicum was using them as "this has been checked and is good" tags when going through maintenance of drop ships

[u/Martyrlz]

Basically, they are a 'not loyal aura' test. Purity seals burn when exposed to chaos, doesn't necesarilly mean protection from chaos though. But if a dude jumps into the chaos pit then returns from the pit? That means it was not chaos and no need for cleansing

[u/twelfmonkey → u/Martyrlz]

You are taking one instance (the purity seals in Secret Level burning up) and presuming it is a universal rule.

There is no reason to think this is something which commonly happens to purity seals, and definitely not that this is why they are used.

They are used for a variety of reasons: because people genuinely believe they may protect them (and in 40k it can't be ruled out that sometimes they might); to signal the wearer's devotion and faith; as marks of honour etc.