Not only are wax seals decorative, but they have a security element too: No nosy house-keeper could peek in to your written missives without breaking your wax seal.
But a paltry little red wax seal on the back of an envelope is not touching the sides of what security elements can be put in place with wax and paper. Friends, I have stumbled into another world; the world of letter locking and if you have not heard of it, you are going to LOVE IT SICK. Read on ....
Picture the scene: Mary Queen of Scots knows that she is in trouble and sends one final urgent and pleading letter to her brother in law - the King of France. No wee piddly bit of sealing wax is going to be secure enough for this missive .... she secures it with a Butterfly Lock, demonstrated here for your delight and delectation.
BTW - these videos are a pure delight if you are also ASMR inclined .....
Simeon Fox, the 'intelligencer' who used this technique to secure his letters back to Blighty was actually a physician. Indeed, his Wiki page only refers to his doctorly deeds and makes no reference to any intelligence that he sent back to Sir Robert Cecil. Which he most definitely did. The naughty man.
This makes cunning use of slits, paper daggers, wax and threads. And probably takes about as long to carry out as write the letter in the first place. But the end result is a very innocent looking missive ... who would suspect such a thing?!
Subscribe to their fascinating youtube channel and read more about the MIT team behind all the research here, in Atlas Obscura. More links to articles can be found at the MIT Libraries page.
Sending (and receiving!) Christmas cards this year is going to be veeerrrrry interesting!