Venerating the departed is a deeply rooted tradition in Asia, where it is believed that when someone dies, his spirit keeps on living in the afterlife and has to be supported in that other life by its successors and descendants in this life.
The system to ‘ship’ sustenance to the other side is through burning them. Of course, nobody sets a real house on fire to make it appear on the aunt’s side of hell, a pile of clothes and even less real money, so the right way to do it is through paper reproductions of whatever you want to give as a gift.
As the departed are doing there as they did in here, it is mandatory for them to have money to spend (oil prices are rushing everywhere, you know), a house where to live, a car, fancy clothes, watches, the latest mobile phone model, even guitars to keep on rocking: whatever necessary to make the ‘living’ of the deceased more comfortable on the other side.
Being money the prime instrument to buy goods here, so it is there. Joss paper is (also known as ghost money, spirit money or even with the cool name of shadow money) the substitute for real bank notes. There are two types: the traditional ones, with a side stamped with gold or silver depending on the ‘value’:
And the contemporary designs, known as Hell Bank Notes or Hell money. This modern joss paper, under “Hell Bank” note denominations, mimic real currency, adding some details from the afterlife, with a value ranging from 100 to several billions (dollars, HKD, or whatever is the local currency).
Note that the denomination ‘hell’ in these banknotes does not have any negative connotation, as it happens with western religious traditions: ‘hell’ is just the name of the other life. This confusion comes after the first missionaries in Asia started preaching that all those Taoist non-believers would “go to hell” after death…
By the way, ‘joss’ is supposed to be a corrupted version of the Portuguese word for ‘god’: deus.