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I'm flying off at tangent here, away from my OP, in a way. There was an article in one of the papers to celebrate the 800th anniversary of the Magna Carta in 2012. Lots of info given, except one thing, which I wrote to them about. That was the ink that was used to write it. Made to a special formula of natural ingredients, the basis of it is still in use today and is only available to govt officials. This is because, unlike normal ink, which fades with age, the ancient ink darkens with age and is the reason why people can read govt documents from hundreds of years ago and all the census data from the very beginning.