The contract is written on the tanned hide of a water buffalo in the dark cuttlefish ink that the Ma’dan made by crushing the ink sac of the marsh cuttlefish and mixing it with gum arabic and water. The ink is nearly black, blacker than the oak-gall ink of the cities, and it has a faint iridescence when the light catches it at an angle, a sheen like oil on water. There was no such light in the archives.